JP6875645B2 - Measuring device - Google Patents

Description

In the present invention, the potential difference measuring electrode (pH electrode, oxidation-reduction potential difference measuring electrode (ORP electrode), ion electrode), electrical conductivity cell, oxidation-reduction current measuring electrode (dissolved oxygen electrode, residual chlorine electrode, etc.) are provided with respect to the main body of the apparatus. ), Pressure sensor, optical sensor (turbidity sensor, optical dissolved oxygen sensor, etc.), etc., by replacing and connecting the probe, potential difference meter (pH meter, oxidation-reduction potential difference meter, ion meter, etc.), electrical conductivity meter , Oxidation-reduction current measuring device (dissolved oxygen meter, residual chlorine meter, etc.), pressure gauge, optical measuring device (turbidity meter, optical dissolved oxygen meter, etc.), etc. It is related to a measuring device that can be used.

Conventionally, for example, there are measuring devices such as a pH meter, an electric conductivity meter, and a dissolved oxygen meter in which a probe provided with a pH electrode, an electric conductivity cell, a dissolved oxygen electrode, and the like is detachable from the device body. However, conventionally, it has generally been necessary to prepare a dedicated device body for each probe to be used. In addition, although some devices are provided with connectors for connecting a plurality of probes, they can only be used as a dedicated measuring device such as a pH meter or an electric conductivity meter.

Patent Document 1 describes, for example, a probe for potentiometric titration measurement (for example, a probe for pH measurement) and a probe for measurement items having a different measurement principle (for example, a probe for electric conductivity measurement). A measuring device that can be arbitrarily replaced and connected to a specific connector of the above and automatically switches to a function corresponding to those probes is disclosed.

Japanese Unexamined Patent Publication No. 2005-1146697

However, in the conventional measuring apparatus described in Patent Document 1, a plurality of measuring circuits corresponding to the measuring items of each probe are provided in the apparatus main body. Then, the corresponding measurement circuit is automatically switched and used by a switching circuit such as a relay according to the probe connected to the main body of the device. Therefore, it is easy to increase the size and price of the measuring device due to the provision of a plurality of measuring circuits. In addition, the switching circuit consumes a relatively large amount of power, making it difficult to save power.

Further, in the above-mentioned conventional measuring device, an analog signal is transmitted from the probe to the device main body via a cable. Therefore, when the length of the cable is 10 m or more, the wire resistance of the cable has an effect. Therefore, in order to accurately measure the resistance value of the temperature detection element provided in the probe, a 4-wire type is used. Was needed. Further, when an AC bipolar cell is used as the electrical conductivity cell, for the same reason, an instruction error is likely to occur when the cable length is long.

Further, in the above-mentioned conventional measuring device, for a probe such as a probe for pH measurement, which tends to be replaced relatively frequently, it is necessary to replace the probe together with the cable, which is improved from the viewpoint of running cost and reduction of environmental load. There was room.

Therefore, an object of the present invention is to easily utilize functions corresponding to a plurality of measurement items with one measuring device while aiming at miniaturization, price reduction, power saving, running cost reduction, and environmental load reduction. It is to provide a measuring device that can be used.

Further, another object of the present invention is to eliminate the need to calibrate or set a correction value every time the probe is replaced with respect to the main body of the apparatus while achieving the above object, and it is easy to manage the calibration history, the usage state, and the like. Furthermore, it is possible to reduce setting differences and forgetting to set, and to provide a measuring device in which the probe can be easily replaced.

The above object is achieved by the measuring device according to the present invention. In summary, the present invention is a measuring device having a device main body and a probe that can be attached to and detached from the device main body, wherein the probe is a sensor unit having a measuring unit according to a measurement target and the sensor. A measurement circuit that converts an analog signal acquired from the unit into a digital signal related to the measurement result by the sensor unit, and a measurement unit provided with a probe-side connector for detachably connecting the probe to the device main body. a, wherein the sensor unit is detachably attached to the measuring unit, wherein the sensor unit is provided with a memory in which identification information is stored, the apparatus main body, a first sensor unit is first The first probe, which is the probe attached to the measurement unit , and the second sensor unit, which is the probe attached to the second measurement unit, have a second sensor unit whose measurement target is different from that of the first sensor unit. the probe, and the body-side connector connectable detachably replace the probe connector, and display means for displaying by the display means the measurement result by the sensor unit based on the digital signal obtained from the measuring unit A first measuring unit including a control unit that performs display processing, the first measuring unit processes a signal from the first sensor unit and does not process a signal from the second sensor unit as the measuring circuit. The second measurement unit includes, as the measurement circuit, a second measurement circuit that processes a signal from the second sensor unit and does not process a signal from the first sensor unit. the control unit, based on the identification information read from the memory, the display processing, a first display processing conforming to measurement by the first sensor unit, the measurement by the second sensor unit It is a measuring device characterized by automatically switching to a matching second display process.

According to the present invention, it is possible to easily use the functions corresponding to a plurality of measurement items with one measuring device while aiming at miniaturization, price reduction, power saving, running cost reduction, and environmental load reduction.

Further, according to the present invention, while achieving the above-mentioned effects, it is not necessary to calibrate or set a correction value every time the probe is replaced with respect to the apparatus main body, and it is easy to manage the calibration history, the usage state, and the like. Furthermore, it is possible to reduce setting differences and forgetting to set, and it becomes easy to replace the probe.

It is a schematic perspective view which shows the whole structure of a measuring device. It is a schematic cross-sectional view of an example of a probe. It is a schematic circuit diagram from an example probe to the main body side connector. It is a schematic circuit diagram from the probe of another example to the connector on the main body side. It is a schematic circuit diagram from the probe of still another example to the connector on the main body side. It is a block circuit diagram of a device main body. It is a flow diagram for demonstrating the operation when a probe is replaced and connected. It is a schematic diagram which shows the example of the display mode of the measurement result. It is a flow diagram for demonstrating the operation of the measuring apparatus including the erroneous mounting notification operation. It is a block circuit diagram of the apparatus main body of a 2-channel measuring apparatus. It is a schematic diagram which shows the example of the display mode of the measurement result of 2 channels. It is a schematic diagram which shows the example of the display mode of the measurement result of other measurement items. It is a flow figure for demonstrating another use mode of a sensor memory.

Hereinafter, the measuring device according to the present invention will be described in more detail with reference to the drawings.

[Example 1]
FIG. 1 is a schematic perspective view showing the overall configuration of the measuring device 1 of this embodiment. The measuring device 1 has a device main body 2 and a probe 3 that can be attached to and detached from the device main body 2. In this embodiment, the measuring device 1 includes, as the probe 3, a pH measuring probe (also referred to as “pH probe”) 3A having a pH electrode which is a potentiometric titration electrode, and electricity including an electric conductivity cell. A probe for measuring conductivity (also referred to as "EC probe" here) 3B and a probe for measuring dissolved oxygen provided with a dissolved oxygen electrode which is an oxidation-reduction current measuring electrode (also referred to as "DO probe" here). The 3C can be replaced and used (Fig. 6). When the elements commonly provided in the pH probe 3A, the EC probe 3B, and the DO probe 3C are generally described, A, B, and C at the end of the reference numerals indicating that the elements belong to any of the probes are used. Omit. FIG. 1 shows a pH probe 3A as an example of the probe 3.

The probe 3 has a sensor unit 4 and a measurement unit 5. The sensor unit 4 has a measuring unit 41 according to the measurement target. For example, in the case of the pH probe 3A shown in FIG. 1, the sensor unit 4A is an elongated pH electrode having a pH-sensitive portion such as a glass-sensitive film as a measuring portion 41A at the lower tip portion in the drawing. .. Further, the sensor unit 4A has a sensor memory 42A which is a storage means as an identification means to which the identification information regarding the probe 3A is attached. On the other hand, the measurement unit 5A has a measurement circuit 51A that converts an analog signal acquired from the sensor unit 4A into a digital signal indicating the measurement result of the sensor unit 4A. In the case of the pH probe 3A shown in FIG. 1, the measurement circuit 51 is a measurement circuit for pH measurement, which is a measurement circuit for measuring the potential difference. Further, the measuring unit 5A has a probe-side connector 52A connected to the measuring circuit 51A via the cable 55A for detachably connecting the probe 3 to the device main body 2.

As shown in FIG. 4, the EC probe 3B includes a sensor unit 4B including a measuring unit 41B and a sensor memory 42B, which is an elongated electrically conductive cell as a whole, and a measuring unit 5C. The measurement unit 5C of the EC probe 3B includes a measurement circuit 51B for measuring electrical conductivity and a probe-side connector 52B connected to the measurement circuit 51B via a cable 55B. Then, the EC probe 3B is detachably connected to the main body side connector 22 provided on the device main body 2 by the probe side connector 52B. Further, as shown in FIG. 5, the DO probe 3C includes a sensor unit 4C including a measuring unit 41C and a sensor memory 42C, which is an elongated dissolved oxygen electrode as a whole, and a measuring unit 5C. The measurement unit 5C of the DO probe 3C includes a measurement circuit 51C for measuring dissolved oxygen, which is a measurement circuit for measuring redox current, and a probe-side connector 52C connected to the measurement circuit 51C via a cable 55B. There is. Then, the DO probe 3C is detachably connected to the main body side connector 22 provided on the device main body 2 by the probe side connector 52C.

The probe 3 will be further described. FIG. 2 is a schematic cross-sectional view of the pH probe 3A as an example of the probe 3. In this embodiment, the sensor unit 4 is removable from the measuring unit 5. The sensor unit 4 includes a first inter-unit connector (sensor unit side connector) 44, and the measurement unit 5 is a second inter-unit connector (measurement) that is detachably connected to the first inter-unit connector 44. The unit side connector) 54 is provided. That is, the sensor unit 4 has a first substrate (sensor unit substrate) 43 which is a printed circuit board adjacent to an end portion (base end portion) opposite to the end portion (tip portion) on the measurement unit 41 side. However, the sensor memory 42 and the first inter-unit connector 44 are provided on the first substrate 43. Further, the measurement unit 5 has a second substrate (measurement unit substrate) 53 which is a printed circuit board, and the measurement circuit 51 and the second inter-unit connector 54 are provided on the second substrate 53. ing. The first inter-unit connector 44 is arranged in the sensor unit 4 so as to be exposed from the base end portion of the substantially elongated cylindrical sensor unit 4. Further, the measurement unit 5 has a recess 8 into which the base end portion of the sensor unit 4 is inserted, and the second inter-unit connector 54 is arranged in the measurement unit 5 so as to be exposed in the recess 8. Then, in the probe 3, the sensor unit 4 and the measurement unit 5 are fitted by inserting the base end portion of the sensor unit 4 into the recess 8 of the measurement unit 5, and the first and second inter-unit connectors 44, It is integrated by connecting 54. Further, the wiring drawn from the measurement circuit 51 of the measurement unit 5 is bundled as a cable 55 and connected to the probe-side connector 52. The probe 3 is detachably connected to the main body side connector 22 provided on the device main body 2 by the probe side connector 52 via the cable 55. The recess 8 of the measurement unit 5 is provided with an O-ring 6 as a sealing member that liquidally seals the space between the sensor unit 4 and the outer peripheral surface in the vicinity of the base end portion. Further, in this embodiment, the sensor unit 4 is slid and fitted into the recess 8 of the measurement unit 5. Then, the sensor unit 4 is fixed to the measurement unit 5 by screwing the bag nut 7 as a fixing member arranged so as to surround the outer circumference of the sensor unit 4 to the end of the measurement unit 5 on the sensor unit 4 side. It is supposed to be done.

In this embodiment, EEPROM (Electrically Erasable Programmable Read-Only Memory), which is a storage means, is used as the identification means. However, the present invention is not limited to this. As the identification means, storage means such as EPROM, flash memory, RAM with battery backup, EPROM, one-time ROM, CPU with memory; physical quantity or state changing means such as switch, analog switch, resistor, capacitor; voltage generator, Physical quantity generating means such as a current generator and a light generator; a change in the physical shape of the sensor unit 4; or a bar code or the like can also be used. Identification information about the probe 3 is attached to these identification means. The identification information regarding the probe 3 includes at least identification information regarding the sensor unit 4, such as information such as the type (measurement item), model name, and serial number of the sensor unit 4. Further, the identification information regarding the probe 3 includes identification information regarding the measurement unit 5 corresponding to the sensor unit 4, for example, information such as the type (measurement item) and model name of the measurement circuit 51 incorporated in the measurement unit 5. Good. The identification information about the sensor unit 4 may also serve as the identification information about the measurement unit 5 corresponding to the sensor unit 4. When it is not necessary to assume the case where the sensor unit 4 and the measurement unit 5 described later are erroneously mounted, for example, when the sensor unit 4 is for pH measurement, the measurement unit 5 is also for pH measurement. Is.

On the other hand, the apparatus main body 2 is provided with a recognition means for recognizing the information attached to the identification means. In this embodiment, the CPU 21 of the device main body 2 described later functions as a recognition means for reading and recognizing the information stored in the sensor memory 42. Here, the recognition means of the device main body 2 to recognize the information attached to the identification means is not limited to directly reading and recognizing the information attached to the identification means. The reading means provided in the measurement unit 5 of the probe 3 reads (further recognizes) the information attached to the identification means, and the recognition means recognizes the information indicating the reading result (further recognition result). Also includes. The information indicating the reading result (furthermore, the recognition result) is not limited to the information itself attached to the identification information, and the output (display, etc.) of the measurement result described later to the CPU 21 of the apparatus main body 2 and the operation unit. It may be information that instructs switching of functions. The reading means may be capable of reading (further recognizing) the information attached to the identification means in response to the various identification means. For example, when the identifying means is a physical quantity or a state changing means, the reading means is used as a means for reading the physical quantity or the change (difference) in the state, and if the identifying means is a physical quantity generating means, the reading means receives the physical quantity. If the identification means is a physical shape change (difference) of the probe, it is used as a means for reading the physical shape change, and if the identification means is a barcode, the reading means reads the barcode. It may be a means for reading.

However, the identification means is preferably an electronic memory as a storage means in terms of cost, ease of information transmission, and the amount of information that can be attached. The storage means may be a non-contact type that can wirelessly communicate with the recognition means or the reading means.

FIG. 3 is a schematic circuit diagram from the probe 3 to the main body side connector 22 when the pH probe 3A as an example of the probe 3 is used.

The first substrate 43 included in the sensor unit 4 of the probe 3 is provided with a first inter-unit connector 44 and a sensor memory 42. In the first inter-unit connector 44, pin 1 is connected to the measurement electrode (internal electrode) 61, pin 2 is connected to the measurement electrode signal guard ring, and pin 3 is connected to the comparison electrode (internal electrode) 62. The pins are connected to the sensor memory 42, and the 5th and 6th pins are connected to a temperature sensor (temperature detection element) 63 for temperature compensation provided in the sensor unit 4. In this embodiment, the sensor memory 42, which is an EEPROM, is connected to 6 pins used as a circuit common in addition to the 4 pins. For example, when a resistor is used as the identification means, identification information can be attached as the presence or absence of the resistor connected to the 4 pin and the resistance value of the resistor connected to the 4 pin.

The second substrate 53 included in the measurement unit 5 of the probe 3 includes a second inter-unit connector 54, a measurement circuit 51, a CPU 56 as an arithmetic control means, a communication driver 57, and the present embodiment as a storage means. A measurement unit memory 58, which is an EEPROM, is provided. In the pH probe 3A, the measurement circuit 51 is a measurement circuit for pH measurement. The measurement circuit 51 is provided with an amplifier 511 and an A / D converter 512. The amplifier 511 appropriately amplifies the analog signals (pH measurement signal, temperature measurement signal) acquired from the sensor unit 4. A plurality of amplifiers 511 may be provided corresponding to the signal input to the measurement unit 5. The A / D converter 512 converts the analog signal amplified by the amplifier 511 into a digital signal indicating the measurement result of the sensor unit 4. The CPU 56 of the measurement unit 5 comprehensively controls the processing (operation) in the probe 3. In particular, the CPU 56 of the measurement unit 5 processes (corrects, etc.) the digital signal acquired from the A / D converter 512 to obtain the measurement result (measured value) of the sensor unit 4. The communication driver 57 controls the transmission of a digital signal between the CPU 56 of the measurement unit 5 and the device main body 2. The measurement unit memory 58 stores procedures and data for controlling processing in the probe 3. In particular, in this embodiment, the measurement unit memory 58 stores procedures and data for calculating and outputting measurement results (pH value, electrical conductivity value, dissolved oxygen concentration value, temperature value). As the measurement unit memory 58, an EEPROM, a flash memory, a RAM with a battery backup, an EPROM, a one-time ROM, or the like can be appropriately used. Pins 1 to 6 of the second inter-unit connector 54 are connected to pins 1 to 6 of the first inter-unit connector 44, respectively. In the second inter-unit connector 54, pins 1 and 3 are connected to the amplifier 511 for pH measurement, pins 5 and 6 are connected to the amplifier 511 for temperature measurement, and pin 2 is connected to the measurement electrode signal guard ring. It is connected and pin 4 is connected to the CPU 56 of the measurement unit 5.

A probe-side connector 52 is provided at the end of the cable 55 containing the wiring drawn from the measurement unit 5. In the probe side connector 52, pin 1 is for GND (for power supply), pin 2 is for power supply (+ 5V), pins 3 and 4 are for data transmission (+/-), and pin 5 is for GND (for shield). Pin 6 is a pin for identifying the presence or absence of a probe.

Further, the device main body 2 is provided with a main body side connector 22. Pins 1 to 6 of the probe-side connector 52 are connected to pins 1 to 6 of the main body-side connector 22, respectively. In the main body side connector 22, pin 1 is for GND (for power supply) and pin 2 is for power supply (+ 5V), which is connected to the probe power supply circuit 24 described later. Further, in the main body side connector 22, pins 3 and 4 are pins for data transmission (+/-) and are connected to a digital signal processing circuit 23 described later. Further, in the main body side connector 22, pin 5 is a pin for GND (for shielding) and is connected to GND. Further, in the main body side connector 22, pin 6 is a pin for identifying the presence / absence of a probe, and is connected to a probe presence / absence identification circuit 25 described later.

4 and 5 are schematic circuit diagrams from the probe 3 to the main body side connector 22 when the EC probe 3B and the DO probe 3C as other examples of the probe 3 are used, respectively. In FIGS. 4 and 5, elements having the same or corresponding functions or configurations as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 4, when the EC probe 3B is used, in the first inter-unit connector 44, pin 1 is connected to the platinum black electrode 64 for detection, pin 2 is connected to the detection signal guard ring, and pin 3 Is connected to a platinum black electrode 65 for applying a voltage. When the EC probe 3B is used, the measurement circuit 51 is a measurement circuit for measuring electrical conductivity. A voltage application unit 513 is provided in the measurement circuit 51 for measuring the electrical conductivity. When the EC probe 3B is used, in the second inter-unit connector 54, pin 1 is connected to the amplifier 511 for measuring electrical conductivity, pin 3 is connected to the voltage application unit 513, and pin 2 is the detection signal guard. It is connected to the ring.

As shown in FIG. 5, when the DO probe 3C is used, in the first inter-unit connector 44, pin 1 is connected to the working electrode 66, pin 2 is connected to the detection signal guard ring, and pin 3 is connected to the counter electrode 67. It is connected. When the DO probe 3C is used, the measurement circuit 51 is a measurement circuit for measuring dissolved oxygen. The measurement circuit 51 for measuring dissolved oxygen is provided with a voltage application unit 513. When the DO probe 3C is used, in the second inter-unit connector 54, pin 1 is connected to the amplifier 511 for measuring dissolved oxygen, pin 3 is connected to the voltage application unit 513, and pin 2 is the detection signal guard ring. It is connected to the.

Here, in this embodiment, the sensor unit 4A of the pH probe 3A is a composite electrode in which a measurement electrode (glass electrode) and a comparison electrode are integrated. Then, the measuring circuit 51A for pH measurement included in the measuring unit 5A of the pH probe 3A detects the electromotive force generated in the glass-sensitive film by measuring the potential difference between the two poles with a voltmeter.

Further, in this embodiment, the sensor unit 4B of the EC probe 3B is an AC two-pole system using a platinum black electrode. Then, the measuring circuit 51B for measuring the electrical conductivity included in the measuring unit 5B of the EC probe 3B applies an AC voltage between the two poles, measures the current flowing at that time with an ammeter, and detects the impedance.

Further, in this embodiment, the sensor unit 4C of the DO probe 3C is a diaphragm type polarograph type electrode having a working electrode and a counter electrode in the sensor unit 4C partitioned by an oxygen gas permeable diaphragm. Then, the measuring circuit 51C for measuring dissolved oxygen included in the measuring unit 5C of the DO probe 3C applies a DC voltage between the two poles, and uses an ammeter to measure the current that flows when the oxygen that has passed through the diaphragm is reduced at the working pole. By measuring, the diffusion current proportional to the dissolved oxygen is detected.

The measurement circuits 51A, 51B, and 51C for pH measurement, electrical conductivity measurement, and dissolved oxygen measurement have different measurement principles and different circuit configurations. As described above, in the measuring device described in Patent Document 1, a plurality of measuring circuits corresponding to each of these different measurement items are provided in the device main body of the measuring device. Then, the measurement circuit was switched by a switching circuit such as a relay according to the probe connected to the main body of the apparatus and used. Therefore, in the above-mentioned conventional measuring device, the measuring device tends to be large and expensive. In addition, the switching circuit consumes a relatively large amount of power, making it difficult to save power. On the other hand, in this embodiment, since the measurement circuit 51 is provided in the measurement unit 5 of the probe 3, the apparatus main body 2 can acquire the measurement value-related information by the digital signal. Therefore, it is not necessary to provide a switching circuit such as a relay or a plurality of measurement circuits in the device main body 2, and it is possible to reduce the size, price, and power consumption of the device main body 2. For example, it is possible to achieve a battery life of several hundred hours by using two AA alkaline batteries (3V, 2000mAh). Therefore, the main body of the device is not limited to the desktop installation type, and it is easy to make it a portable handy type.

Further, in this embodiment, the temperature sensor (temperature detection element) 63 provided in the probe 3 is composed of a two-wire thermistor type resistor (temperature measuring body, resistance type temperature measuring body electrode). As described above, in the measuring device described in Patent Document 1, an analog signal is transmitted from the probe to the device main body via the cable. Therefore, in view of the influence of the line resistance of the cable when the cable length is long, A 4-wire type temperature sensor was required. On the other hand, in this embodiment, the measurement unit 5 of the probe 3 is provided with a measurement circuit for a temperature sensor, and the distance between the temperature sensor of the sensor unit 4 and the measurement circuit is short. There is no influence of. Then, by transmitting a digital signal between the probe 3 and the apparatus main body 2, long-distance communication is possible without considering the influence of the line resistance. Therefore, in this embodiment, the temperature can be measured accurately by the two-wire temperature sensor. That is, the number of signals for the temperature sensor (number of wires, number of connector pins) can be reduced, and the probe 3 (sensor unit 4, measurement unit 5, inter-unit connector) can be miniaturized and the price can be reduced. Is.

Further, as described above, in the measuring device described in Patent Document 1, when an AC bipolar type, for example, is used as the electric conductivity cell, it is instructed that the length of the cable becomes long due to the influence of the same line resistance as described above. Errors were likely to occur. On the other hand, in this embodiment, the measurement unit 5 of the probe 3 is provided with the measurement circuit for the electric conductivity cell, and the distance between the electric conductivity cell of the sensor unit 4 and the measurement circuit is short. , There is no influence of the above line resistance. Then, by transmitting a digital signal between the probe 3 and the apparatus main body 2, long-distance communication is possible without considering the influence of the line resistance. Therefore, in this embodiment, for example, even when an AC bipolar type electric conductivity cell is used, the electric conductivity can be measured with high accuracy.

In this embodiment, the shapes and pin configurations of the first and second inter-unit connectors 44 and 54 of each probe 3 are the same. As a result, the parts can be shared by each probe 3, and the manufacturing cost can be reduced. Further, in this embodiment, the shape and pin configuration of the probe-side connector 52 of each probe 3 are the same, and both can be connected to one main body-side connector 22 common in this embodiment. As described above, in the measuring device described in Patent Document 1, an analog signal is transmitted from the probe to the device main body via a cable, so that the shell of the connector connecting the probe and the device main body is for a minute analog signal. It was a thing. Therefore, a resin having high insulation performance such as a fluororesin is required especially for pH measurement and the like. On the other hand, in this embodiment, a measuring circuit is provided in the measuring unit 5 of the probe 3, and the transmission of the measured value-related information between the probe 3 and the apparatus main body 2 is a digital signal (digital communication 2 lines). Therefore, the above-mentioned high insulation is not required, and the degree of freedom in selecting the resin material of the connector can be increased. Further, in the measuring device described in Patent Document 1, the connector for connecting the probe and the device main body has pins that are specific to a specific type of probe and are not necessary for other types of probes. Therefore, the number of pins of the connector as a whole has increased (14 pins). On the other hand, in this embodiment, as described above, the signal related to the measured value between the probe 3 and the apparatus main body 2 is a digital signal (digital communication 2-wire type) in any probe 3, so that the connector The number of pins can be reduced (6 pins), and the probe 3 and the device main body (particularly the connector) can be miniaturized and the price can be reduced. One of the pins (contact members) connected to each other may be a pin receiving hole (contact member). Further, regarding the transmission of the digital signal between the probe 3 and the device main body 2, the probe 3 and the device main body 2 can be connected not only by electrical connection but also by optical coupling means. Is.

FIG. 6 is a block circuit diagram of the device main body 2. The apparatus main body 2 replaces the probe-side connectors 52 of the first probe (for example, pH probe 3A) and the second probe (for example, EC probe 3B or DO probe 3C), which are probes 3 having different measurement circuits 51 from each other. It has a main body side connector 22 that can be detachably connected. The configuration of the pins of the main body side connector 22 is as described above. Further, the apparatus main body 2 includes a digital signal processing circuit 23 as a digital signal processing means, a probe power supply circuit 24 as a probe power supply means, a probe presence / absence identification circuit 25 as a probe presence / absence identification means, and an arithmetic control means. CPU (control unit) 21 as an operation means, an operation unit 26 such as an operation key as an operation means, a display unit 27 such as a liquid crystal display as a display means, and a main body memory which is an EEPROM in this embodiment as a storage means. 28 and a power supply unit 29 are provided. The digital signal processing circuit 23, the probe power supply circuit 24, the probe presence / absence identification circuit 25, the operation unit 26, the display unit 27, and the main body memory 28 are connected to the CPU 21 of the main body 2. Further, each part of the device main body 2 operates by the electric power supplied from the power supply part 29.

The digital signal processing circuit 23 acquires a digital signal from the probe 3 and transmits it to the CPU 21 of the apparatus main body 2 for processing such as outputting a measurement result. The probe power supply circuit 24 supplies power to the probe 3. Each part of the probe 3 operates by the electric power supplied from the probe power supply circuit 24. The probe presence / absence identification circuit 25 identifies and identifies the presence / absence of the probe 3 connection based on the presence / absence of the probe presence / absence identification pin connection in the probe side connector 52 with respect to the probe presence / absence identification pin in the main body side connector 22. A signal indicating the result is transmitted to the CPU 21 of the device main body 2. The CPU 21 of the device main body 2 comprehensively controls the processing (operation) in the device main body 2. In particular, the CPU 21 of the device main body 2 performs a process of outputting the measurement result of the probe 3 based on the digital signal acquired from the probe 3. The operation unit 26 receives instructions such as start / stop of measurement and input of various settings by the user (operator), and transmits the instructions to the CPU 21 of the device main body 2. The display unit 27 displays the measurement result, displays the setting screen for various settings, and the like under the control of the CPU 21 of the device main body 2. The main body memory 28 stores procedures and data for controlling processing in the main body 2. In particular, in this embodiment, the main body memory 28 outputs measurement results (pH value, electrical conductivity value, dissolved oxygen concentration value, temperature value) according to the probe 3 connected as described later (display, etc.). The procedure and data for switching the setting operation by the operation unit 26 according to the connected probe 3 and the data for switching the setting operation are stored. Further, the measurement result can be stored in the main body memory 28. As the main body memory 28, an EEPROM, a flash memory, a RAM with a battery backup, an EPROM, a one-time ROM, or the like can be appropriately used.

Then, in this embodiment, the CPU 21 of the device main body 2 performs a process of outputting the measurement result to the device main body 2 based on the identification information indicated by the sensor memory 42 included in the sensor unit 4 of the probe 3 (1st probe). For example, the first process when the pH probe 3A) is connected and the second process when the second probe (for example, EC probe 3B or DO probe 3C) is connected to the apparatus main body 2. Switch automatically. In this embodiment, the CPU 21 of the device main body 2 further applies the function of the operation unit 26 provided in the device main body 2 to the device main body 2 based on the identification information indicated by the sensor memory 42, such as a pH probe (for example, a pH probe). Automatically to the first function when 3A) is connected and the second function when a second probe (for example, EC probe 3B or DO probe 3C) is connected to the apparatus main body 2. Switch.

For example, when the probe side connector 52A of the pH probe 3A is connected to the main body side connector 22 of the device main body 2, each pin of the probe side connector 52A and each pin of the main body side connector 22 are connected, and the probe 3A and the device main body 2 are connected. It is possible to send and receive digital signals between the devices, supply power from the device main body 2 to the probe 3A, and identify the presence or absence of the probe 3A. Then, the CPU 21 of the device main body 2 that functions as the recognition means reads the identification information stored in the sensor memory 42A of the sensor unit 4A of the probe 3A as the identification means via the measurement unit 5A of the probe 3A, and reads the identification information. Recognize that the probe 3 connected to the main body 2 is the pH probe 3A. Further, when the CPU 21 of the apparatus main body 2 recognizes that the pH probe 3A is connected, the display on the display unit 27 is switched to the display for pH measurement as shown in FIG. 8A, and the pH value, temperature value, etc. Is displayed. The processing for outputting the measurement result includes a process for displaying the measurement result on the display unit 27, a process for printing and outputting the measurement result by a printer provided on the device main body 2 or connected to the device main body 2, and a process for outputting the measurement result. It may be at least one of the processes of outputting a signal related to the measurement result to the external device for displaying by a display means in an external device such as a personal computer communicatively connected to 2. In addition, the CPU 21 of the main body 2 also has functions adapted to pH measurement, such as setting operations by the user in the operation unit 26, such as start / stop of pH measurement and calibration of pH electrodes. Switch to start / stop operation.

Similarly, when the EC probe 3B is connected to the device main body 2, the CPU 21 of the device main body 2 reads the identification information stored in the sensor memory 42B via the measurement unit 5B, and the EC probe 3B is connected. Recognize that it was done. Then, the CPU 21 of the apparatus main body 2 switches the display on the display unit 27 to the display for measuring the electrical conductivity (electrical conductivity value, temperature value, etc.) as shown in FIG. 8B, and further, the operation unit 26 Switch the function to the function for measuring electrical conductivity.

Similarly, when the DO probe 3C is connected to the device main body 2, the CPU 21 of the device main body 2 reads the identification information stored in the sensor memory 42C via the measurement unit 5C, and the DO probe 3C Recognize that is connected. Then, the CPU 21 of the device main body 2 switches the display on the display unit 27 to a display for measuring dissolved oxygen (dissolved oxygen concentration value, temperature value, etc.) as shown in FIG. 8 (c), and further functions of the operation unit 26. To the function for measuring dissolved oxygen.

As described above, the CPU 56 of the measurement unit 5A as the reading means reads (further recognizes) the identification information stored in the sensor memory 42A, and information indicating the reading result (further recognition result). The CPU 21 of the device main body 2 as a recognition means may be configured to recognize the probe 3 connected to the device main body 2.

Next, the operation of the measuring device 1 when the probe 3 is replaced with the device main body 2 and connected will be described. FIG. 7 is a flowchart showing an outline of the procedure of this operation.

First, the CPU 21 of the device main body 2 reads the identification result of the probe presence / absence identification circuit 25 (S101), and determines whether or not the probe 3 is connected to the device main body 2 (S102). This operation is performed when the probe 3 is connected to the device main body 2, when the power of the measuring device 1 is turned on after the probe 3 is connected to the device main body 2, or every time the power of the measuring device 1 is turned on. It can be carried out. When the CPU 21 of the device main body 2 determines in S102 that the probe 3 is connected, the CPU 21 reads the identification information from the sensor memory 42 via the measurement unit 5 (S103). In this embodiment, the sensor memory 42 stores the calibration data (or correction value) of the sensor unit 4 in addition to the identification information. Then, in S103, the CPU 56 of the measurement unit 5 reads the identification information from the sensor memory 42 and transmits it to the CPU 21 of the device main body 2, and also reads the calibration data (or correction value) from the sensor memory 42 to read the measurement unit. It is stored in the memory 58 (or the storage unit in the CPU 56 of the measurement unit 5). An example of control using the information stored in the sensor memory 42 in addition to the identification information will be described in more detail later (Example 4). In this way, by reading the information stored in the sensor memory 42 prior to the measurement, it is possible to suppress the reading of the information from affecting the measurement. Next, the CPU 21 of the apparatus main body 2 recognizes which of the pH probe 3A, the EC probe 3B, and the DO probe 3C is connected (S104).

Next, when the pH probe 3A is connected to the device main body 2, the CPU 21 of the device main body 2 switches functions such as display on the display unit 27 and setting operation on the operation unit 26 for pH measurement (S105A). .. In parallel with S105A, or before or after S105A, the CPU 56A of the measurement unit 5A reads the digital signal corresponding to the output of the sensor unit (pH electrode, temperature sensor) 4A generated by the measurement circuit 51A, and reads the above-mentioned calibration data. The pH value is calculated using the above, and a digital signal indicating the pH value (further temperature) is transmitted to the CPU 21 of the main body 2 (S106A). Then, the CPU 21 of the apparatus main body 2 generates a signal for displaying the pH value (further, the temperature) on the display unit 27 according to the digital signal acquired from the measurement unit 5A, and the pH value (further, further, the temperature) is displayed on the display unit 27. Temperature) is displayed (S107A). Similarly, when the EC probe 3B is connected, the electric conductivity value (further temperature) is output by S105B to 107B, and when the DO probe 3C is connected, the dissolved oxygen concentration value is output by S105C to 107C. (Furthermore, temperature) is output.

Further, when the CPU 21 of the apparatus main body 2 determines in S102 that the probe 3 is not connected, the CPU 21 of the apparatus main body 2 switches the operation mode of the measuring apparatus 1 from the measurement mode (normal mode) capable of measuring to the power saving mode (S108). .. In this embodiment, the probe power supply circuit 24 is turned off in the power saving mode. In this way, the CPU 21 of the device main body 2 stops the power supply from the probe power supply circuit 24 to the probe 3 when it is identified by the probe presence / absence identification circuit 25 that the probe 3 is not connected to the main body side connector 22. Alternatively, the prohibition control can be performed. As a result, the power consumption in the standby state can be reduced, and the power saving of the measuring device 1 can be achieved. Further, in the power saving mode, it is possible to take any measures that can reduce the power consumption as compared with that during the measurement, such as turning off the backlight of the display unit 27 (or lowering the illuminance).

As described above, in this embodiment, one device main body 2 is used as a pH meter, an electric conductivity meter, and a dissolved oxygen meter very simply by replacing the probe 3 to be used and connecting it to the device main body 2. be able to. Moreover, since each probe 3 can be connected to the same main body side connector 22, the user is not bothered by selecting the connection destination of the probe 3. As described above, according to this embodiment, for each measurement item, for example, the potential difference (pH, redox potential difference, ion concentration) and other electrical conductivity, redox current (dissolved oxygen concentration, residual chlorine concentration, etc.) There is no need to prepare a dedicated measuring device for each measurement item such as pressure, optical measurement target (turbidity, etc.), and many items can be obtained with one measuring device 1 simply by replacing and connecting the probe 3. Can be measured. Then, the process of automatically outputting the measurement result based on the identification information stored in the sensor memory 42 on the device main body 2 side is switched, and further, the function of the operation unit 26 is switched, so that it is used according to the connected probe 3. It is possible to reduce the operational burden on the user, such as the user resetting the display function and the operation function.

Further, in this embodiment, the probe 3 has a configuration in which the sensor unit 4 is detachable from the measurement unit 5. Therefore, when the sensor unit 4 is worn out or damaged and needs to be replaced, only the sensor unit 4 can be replaced with a new sensor unit 4 of the same type, and the measurement unit 5 (measurement circuit 51 or cable) can be replaced. 55 etc.) can be used continuously. Therefore, the running cost of the measuring device 1 can be reduced and the environmental load can be reduced. Further, for example, a pH electrode and an ORP electrode (or an ion electrode) which are potential difference measuring electrodes, a dissolved oxygen electrode and a residual chlorine electrode which are oxidation-reduction current measuring electrodes, and a polarograph type electrode and a galvanized type electrode. In addition, for different types of sensor units 4 that share the same measurement principle and can share the measurement circuit 51, different types of sensor units 4 may be replaced and connected to one measurement unit 5. Can be done. Therefore, regarding the measurement unit 5 that can be shared, the need to prepare a new measurement unit 5 can be reduced, which is excellent from the viewpoint of economic efficiency and reduction of environmental load.

As described above, according to the present embodiment, at least one of the first and second probes can replace one sensor unit 4 of the same type with the same measurement target for one measurement unit 5. It is possible. Further, according to the present embodiment, the measurement unit 5 can be shared with one measurement unit 5, and different types of sensor units 4 having different measurement targets can be replaced. Moreover, both of these may be possible. In this embodiment, since the sensor unit 4 is provided with an identification means such as a sensor memory 42, even if the sensor unit 4 is replaced in this way, the apparatus main body 2 is attached to each probe 3 based on the identification information. The process of outputting the measurement result can be automatically switched accordingly, and further, the function of the operation unit 26 can be automatically switched. Further, as will be described in detail later (Example 4), if information such as calibration data is stored in the sensor memory 42 in addition to the identification information, the convenience when the sensor unit 4 is replaced in this way is further improved. ..

When a plurality of types of sensor units 4 capable of using the same measurement circuit such as a pH electrode, an ORP electrode, and an ion electrode can be replaced with one measurement unit 5 and mounted, the measurement unit is used. The memory 58 can store the processing procedure and data in the measurement unit 5 corresponding to each measurement item.

Further, in this embodiment, the sensor unit 4 is provided with a sensor memory 42 which is a storage means as an identification means. On the other hand, the measuring unit 5 may be provided with identification means. As the identification means provided in the measurement unit 5, the measurement unit memory 58, which is a storage means, can be used. However, the present invention is not limited to this, and other identification means described above may be used. The identification means provided in the measurement unit 5 is accompanied by identification information regarding the probe 3. The identification information about the probe 3 attached to the identification means provided in the measurement unit 5 is at least the identification information about the measurement unit 5, for example, the type (measurement item), model name, and serial number of the measurement circuit 51 incorporated in the measurement unit 5. Includes information such as. Further, the identification information regarding the measurement unit 5 may include identification information regarding the sensor unit 4 corresponding to the measurement unit 5, such as information such as the type (measurement item) and model name of the sensor unit 4. The identification information about the measurement unit 5 may also serve as the identification information about the sensor unit 4 corresponding to the measurement unit 5. When it is not necessary to assume the case where the sensor unit 4 and the measurement unit 5 described later are erroneously mounted, for example, when the measurement unit 5 is for pH measurement, the sensor unit 4 is also for pH measurement. Is. In this case, the apparatus main body 2 is provided with a recognition means for recognizing the information attached to the identification means provided in the measurement unit 5. For example, the CPU 21 of the device main body 2 can function as a recognition means for reading and recognizing the information stored in the measurement unit memory 58 as the identification means. However, the present invention is not limited to this, and other reading means and recognition means described above may be used depending on the identification means. Further, the identification means may be provided in both the sensor unit 4 and the measurement unit 5. That is, at least one of the sensor unit 4 and the measurement unit 5 can be provided with the identification means. As a result, the CPU 21 of the device main body 2 as the control unit outputs the measurement result in the same manner as in the above-described embodiment based on the identification information indicated by at least one of the sensor unit 4 and the measurement unit 5. Furthermore, the function of the operating means can be automatically switched.

Here, an example of how to use the identification information when the identification means is provided in both the sensor unit 4 and the measurement unit 5 will be further described. As described above, in this embodiment, the shapes and pin configurations of the first and second inter-unit connectors 44 and 54 of each probe 3 are the same. As a result, the parts can be shared by each probe 3, which is preferable from the viewpoint of reducing the manufacturing cost. On the other hand, in the case of such a configuration, it is possible to assume a case where the user mistakenly attaches the sensor unit 4 which should not be attached to one measurement unit 5. For example, if the sensor unit 4 for measuring the potential difference is erroneously connected to the measuring unit 5 for measuring the redox current that emits an applied signal to the electrodes, the silver chloride internal electrode (pH electrode, ORP electrode, etc.) becomes longer when the connection time becomes longer. The electrode potential of the ion electrode, the inner electrode of the comparison electrode, etc.) may become abnormal, and in some cases, irreversible damage may occur. Therefore, when a sensor unit 4 that does not conform to the measurement unit 5 is connected, processing for notifying the user of erroneous mounting (error display on the display unit 27, alarm by sound, etc.) is performed, or the applied signal is stopped. (Or prohibiting the application of signals) can be performed.

FIG. 9 is a flowchart showing an outline of an operation procedure of the measuring device 1 including an erroneous mounting notification operation of the sensor unit 4. The same step numbers are assigned to the same processes as those described with reference to FIG. 7. First, the CPU 21 of the device main body 2 reads the identification result of the probe presence / absence identification circuit 25 (S101), and determines whether or not the probe 3 is connected to the device main body 2 (S102). In this operation, when the probe 3 is connected to the device main body 2, when the power of the measuring device 1 is turned on after the probe 3 is connected to the device main body 2, the measurement of the probe 3 connected to the device main body 2 is performed. This can be performed when the power of the measuring device 1 is turned on after the sensor unit 4 is connected to the unit 5, or every time the power of the measuring device 1 is turned on. When the CPU 21 of the device main body 2 determines that the probe 3 is connected in S102, the CPU 21 reads the identification information about the sensor unit 4 from the sensor memory 42 via the measurement unit 5 (S201). Further, the CPU 21 of the device main body 2 reads the identification information about the measurement unit 5 stored in the measurement unit memory 58 (S202). Next, the CPU 21 of the apparatus main body 2 determines whether or not the sensor unit 4 conforms to the measurement unit 5 based on the read identification information regarding the sensor unit 4 and the identification information regarding the measurement unit 5 (S203). ).

Then, when the CPU 21 of the device main body 2 determines that the sensor unit 4 does not conform to the measurement unit 5, an error message is displayed on the display unit 27 and a voice message or a voice message is displayed in order to notify the user of the incorrect mounting. An alarm based on a sound such as a beep is emitted from a speaker or the like as a sounding means provided in the device main body 2 (S204). The process for notifying the user of erroneous wearing is not limited to the above, and is optional, such as display by display means, alarm by sound by sounding means, lighting or blinking of light such as warning light. This can be done by using the notification means of. Further, the notification of this erroneous mounting may be performed by the device main body 2 or an external device communicably connected to the device main body 2. Further, the CPU 21 of the apparatus main body 2 displays an error or an alarm when, for example, the sensor unit 4 for measuring the potential difference is erroneously connected to the measuring unit 5 for measuring the redox current that emits an applied signal to the electrodes. In addition or instead, the applied signal can be stopped (or the signal application is prohibited). On the other hand, when the CPU (determination unit) 21 of the apparatus main body 2 determines that the sensor unit 4 is suitable for the measurement unit 5, the process after S103 with reference to FIG. 7 proceeds. The CPU (determination unit) 56 of the measurement unit 5 is based on the identification information about the sensor unit 4 stored in the sensor memory 42 and the identification information about the measurement unit 5 stored in the measurement unit memory 58. , It may be determined whether or not the sensor unit 4 is compatible with the measurement unit 5. In this case, the CPU 56 of the measurement unit 5 sends information indicating the determination result to the device main body 2, and the CPU 21 of the device main body 2 displays an error as described above based on the information indicating the determination result, if necessary. It can be performed.

As described above, according to this embodiment, one measuring device 1 can easily use the functions corresponding to a plurality of measurement items while aiming at miniaturization, price reduction, power saving, running cost reduction, and environmental load reduction. be able to.

[Example 2]
Next, other examples of the present invention will be described. In this embodiment, the measuring device has a plurality of channels, and the probes corresponding to each of the plurality of items can be replaced and used in each channel. In the measuring device of the present embodiment, elements having the same or corresponding functions or configurations as those of the measuring device of the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted (for the following examples). Is the same.) Further, in this embodiment, the elements provided corresponding to each of the channel 1 and the channel 2 described later are distinguished by adding "-1" and "-2" to the end of the reference numerals, respectively.

FIG. 10 is a block circuit diagram of the device main body 2 in this embodiment. In this embodiment, the apparatus main body 2 is provided with two channels, channel 1 (CH1) and channel 2 (CH2). The main body side connector 22, the digital signal processing circuit 23, the probe power supply circuit 24, and the probe presence / absence identification circuit 25 are provided for CH1 and CH2, respectively. Further, also in this embodiment, similarly to the first embodiment, the apparatus main body 2 is provided with a CPU 21, an operation unit 26, a display unit 27, and a main body memory 28.

A plurality of types of probes 3 can be independently connected to the main body side connector 22-1 for CH1 and the main body side connector 22-2 for CH2 as in the first embodiment. Further, the same or different types of probes 3 can be connected to these two main body side connectors 22-1 and 22-2. The operation when any probe 3 is replaced and connected to CH1 and CH2 is the same as that described in the first embodiment, respectively. For example, when the EC probe 3B is connected to CH1 and the pH probe 3A is connected to CH2, the display on the display unit 27 is automatically switched as shown in FIG. 11A. In addition, the functions such as the setting operation in the operation unit 26 are automatically switched to the function suitable for the electric conductivity measurement for CH1 and the function suitable for the pH measurement for CH2. Further, FIG. 11B shows an example of display on the display unit 27 when the pH probe 3A is connected to CH1 and the DO probe 3C is connected to CH2. In other embodiments, for example, the pH probe 3A may be connected to CH1, the EC probe 3B may be connected to CH2, the DO probe 3C may be connected to CH1, and the pH probe 3A may be connected to CH2. Further, the probe 3 corresponding to the same measurement item may be connected to CH1 and CH2.

As described above, according to the present embodiment, the apparatus main body 2 has a plurality of channels, and a plurality of types of probes 3 corresponding to a plurality of measurement items can be arbitrarily connected to the main body side connector 22 of each channel. Then, by simply replacing and connecting the probe 3 used to the main body side connector 22 of each channel, the process of outputting the measurement result according to the individual probe 3 for each channel, and the function of the operation unit 26 are automatically performed. Can be switched to.

In this embodiment, the display function has two channels, but the display function has one channel, and the display of CH1 and CH2 can be switched and used. Further, in this embodiment, two channels are provided as a plurality of channels, but it is also possible to provide more channels and to provide a plurality of main body side connectors corresponding to each channel, such as three or four. ..

[Example 3]
In this embodiment, another aspect of the probe that can be connected by replacing the measuring device will be described.

(I) In Examples 1 and 2, the sensor unit 4 of the probe 3 for potentiometric titration measurement was described as a pH electrode, but at least one of the pH electrode, the redox potentiometric titration measurement electrode (ORP electrode), and the ion electrode It may be selected from the potentiometric titration measuring electrodes including one. Examples of ion-selective electrodes (ion electrodes) other than the pH electrode include sodium ion electrodes, chloride ion electrodes, bromide ion electrodes, iodine ion electrodes, cyanide ion electrodes, cadmium ion electrodes, copper ion electrodes, and silver ion electrodes. Examples thereof include a sulfide ion electrode, a fluoride ion electrode, a potassium ion electrode, a calcium ion electrode, a nitrate ion electrode, an ammonia electrode, and a carbon dioxide gas electrode. It may be another available ion electrode. FIG. 12A shows an example of a display for measuring the ion concentration.

(II) In Examples 1 and 2, the sensor unit 4 of the probe 3 for measuring the redox current was described as being a dissolved oxygen electrode, but a dissolved oxygen electrode, a residual chlorine electrode, a dissolved ozone electrode, and a chlorine dioxide electrode, It may be selected from an oxidation-reduction current measuring electrode including at least one of a chlorite ion electrode, a hydrogen peroxide electrode, and a dissolved hydrogen electrode. These redox current measuring electrodes are, for example, diaphragm type or exposed type polarograph type or galvanic type redox current measuring electrodes. It may be another available redox current measuring electrode. FIG. 12B shows an example of a display for measuring residual chlorine.

(III) The measuring device 1 is used in place of at least one of the probe 3 for potentiometric titration measurement, the probe 3 for electrical conductivity measurement, and the probe 3 for redox current measurement, or in addition to these, as a sensor unit 4. A probe 3 equipped with an optical sensor can be connected and used. Examples of the optical sensor include a turbidity sensor, an optical dissolved oxygen sensor, an absorbance sensor, and a fluorescence sensor. It may be any other available optical sensor.

Examples of the turbidity sensor include a 90 ° scattered light measurement method. The turbidity sensor has, for example, a light emitting unit and a light receiving unit in the sensor unit 4, and the light from the light emitting unit is introduced into the sample liquid introduced into the sample liquid introducing unit provided in the sensor unit 4, and the sample liquid is introduced. A signal corresponding to the amount of light received by the light receiving unit is output. The measurement circuit 51 for measuring turbidity provided in the measurement unit 5 detects a signal emitted by the turbidity sensor according to the amount of scattered light received in the 90 ° direction by injecting light into the sample liquid as described above. Other methods can also be used. FIG. 12C shows an example of a display for measuring turbidity.

As the absorbance sensor, for example, the sensor unit 4 has a light projecting unit, a light receiving unit, and a sample liquid introduction unit, and light is injected from the light projecting unit into the sample liquid in the sample liquid introduction unit to emit light transmitted through the sample liquid. Outputs a signal according to the amount of light detected by the light receiving unit. The measuring circuit 51 for measuring the absorbance provided in the measuring unit 5 irradiates the sample liquid with light from the light projecting unit, and detects a signal emitted by the light receiving unit receiving the transmitted light of the sample liquid as described above.

Further, the fluorescence sensor has, for example, an excitation light projecting unit as an excitation stimulation generating unit and a light receiving unit in the sensor unit 4, and excites the sample liquid introduced into the sample liquid introducing unit provided in the sensor unit 4. The excitation light is irradiated from the light projecting unit, and the fluorescence emitted by the sample liquid is output as a signal corresponding to the amount of light received by the light receiving unit. The measurement circuit 51 for fluorescence measurement provided in the measurement unit 5 irradiates the sample liquid with excitation light from the excitation light projection unit, and emits the excitation light according to the amount of the fluorescence emitted by the sample liquid as described above. Detect the signal. As an optical dissolved oxygen sensor, one is known that detects a shortening of the duration of fluorescence or a decrease in the intensity of fluorescence due to the fluorescence of the fluorescent dye being hindered by the dissolved oxygen. The configuration of this optical dissolved oxygen sensor is substantially the same as that of the fluorescence sensor, but instead of the sample liquid introduction portion, an oxygen permeable film and a fluorescent dye that emits fluorescence by excitation light of a specific wavelength are fixed. It has a fluorescent dye film, and is configured to irradiate the fluorescent dye film with excitation light to generate fluorescence and detect the duration and intensity of fluorescence.

(IV) The measuring device 1 replaces or replaces at least one of the probe 3 for measuring the potential difference, the probe 3 for measuring the electrical conductivity, the probe 3 for measuring the oxidation-reduction current, and the probe 3 for measuring the optical measurement. In addition to these, a probe 3 provided with a pressure sensor (pressure electrode) can be connected as the sensor unit 4 so that it can be used. The pressure sensor is used for atmospheric pressure measurement, pressure correction of this electrode when used together with a diaphragm type electrode, and water depth measurement in a dam or the like.

Examples of the pressure sensor include a diaphragm type pressure sensor and a semiconductor pressure sensor that are well known to those skilled in the art. The diaphragm type pressure sensor has a diaphragm in the probe body as a pressure sensitive element, and converts the displacement of the diaphragm into an electric quantity and outputs it. For example, the diaphragm is a grounded movable electrode, insulated fixed electrodes are placed on both sides of the diaphragm, and the displacement of the diaphragm is converted as the ratio of the voltage across the capacitor by a constant frequency power supply, so that the displacement of the diaphragm is electrostatically signaled. The method of outputting with is well known. Further, as a pressure-sensitive element, a semiconductor pressure sensor has a built-in pressure-sensitive chip such as a piezoresistive element formed on a Si diaphragm and bridge-coupled to the space filled with a gas having a constant pressure such as helium. Is well known. When these pressure sensors can be connected, the pressure measuring measuring circuit 51 provided in the measuring unit 5 applies a voltage to the pressure sensitive element and detects a change in the ratio of the voltages across the capacitors or the electric resistance. Other types of pressure sensors may be used.

(V) Further, the measuring device 1 can be used by connecting a single probe 3 provided with a temperature sensor as the sensor unit 4.

[Example 4]
In this embodiment, the storage means provided in the sensor unit 4 of the probe 3 is used as the identification means to further enhance the convenience. Here, the present embodiment will be described as being applied to the measuring device having the basic configuration of the measuring device 1 of the first embodiment, but it can be equally applied to the measuring device 1 having a plurality of channels described in the second embodiment. is there.

(I) For example, in the pH probe 3A and the DO probe 3C, the characteristics of the probe 3 (more specifically, the sensor unit 4) are calibrated using a standard solution or the like before use, and the measured value is measured based on the calibration result. It is necessary to calculate and correct. Therefore, in addition to the identification information, the sensor memory 42 can store calibration data at the time of inspection of the sensor unit 4 as information about the sensor unit 4. For example, in the sensor memory 42, a model name, a serial number, and the like are stored as identification information when the sensor unit 4 is manufactured, and calibration data is stored as information about the sensor unit 4 when the sensor unit 4 is inspected.

This will be further described with reference to FIG. When the probe 3 is connected to the device main body 2 and the power of the measuring device 1 is turned on, the identification information (model name, model name,) stored in the sensor memory 42 by the CPU 21 of the device main body 2 as described with reference to FIG. Read the serial number, etc.) (S301). The CPU 21 of the device main body 2 determines whether or not the sensor unit (X) is the sensor unit (M) used last time (S302). When the CPU 21 of the device main body 2 determines that the sensor unit (X) is the sensor unit (M) used last time, it is previously read from the sensor memory 42 and measured by the measurement unit memory 58 (or measurement). It is determined to use the previously used calibration data stored in the storage unit in the CPU 56 of the unit 5 (S303). On the other hand, when the CPU 21 of the apparatus main body 2 determines that the sensor unit (X) is not the sensor unit (M) used last time, the CPU 21 reads the calibration data from the sensor memory 42 of the sensor unit (X). , The measurement unit memory 58 (or the storage unit in the CPU 56 of the measurement unit 5) is controlled to store the data (S304). Then, for example, in the case of the pH probe 3A, the measurement unit 5 determines the pH value based on the calibration data stored in the measurement unit memory 58 (or the storage unit in the CPU 56 of the measurement unit 5) and the potential acquired from the sensor unit 4. Calculation correction is performed to obtain the pH value (S305).

Further, the CPU 21 of the device main body 2 may be configured to control the writing of information about the sensor unit 4 such as new calibration data to the sensor memory 42 directly or via the measurement unit 5. For example, when the pH probe 3A is used, calibration data can be obtained by a predetermined calibration procedure using a standard solution, if necessary. For example, after replacing the sensor unit 4, the sensor unit 4 is calibrated before the first measurement using the sensor unit 4 or periodically. In this case, the CPU 21 of the device main body 2 can be controlled to write (update) the acquired new calibration data to the sensor memory 42.

By storing the calibration data in the sensor memory 42 in this way, it is not necessary to calibrate or set the correction value every time the probe 3 is replaced with respect to the apparatus main body 2, and a plurality of probes 3 can be freely used depending on the application and the like. Can be used properly.

(II) For example, in the EC probe 3B, an operation of inputting a cell constant for correcting the sensitivity is required. Therefore, it is possible to store the cell constant in advance in the sensor memory 42 in addition to the identification information. As a result, as described with reference to FIG. 7, when the EC probe 3B is connected to the device main body 2 (or when the power of the measuring device 1 is turned on after that), the cell constant is read from the sensor memory 42. It can be stored in the measurement unit memory 58 (or the storage unit of the CPU 56 of the measurement unit 5) and used for calculation / correction of the measured value. For example, the sensor memory 42 stores a model name, a serial number, and the like as identification information at the time of manufacturing the sensor unit 4, and stores cell constants at the time of inspection. Further, when calibration is performed using the standard solution, the cell constant can be automatically calculated and this value can be stored (updated) in the sensor memory 42. With such a configuration, the cell constant can be automatically set, so that it is possible to reduce forgetting to set or making a mistake.

(III) For example, the pH electrode may need to be tested by the measurement method as in the case of using it for transaction certification. In this case, the validity period of the pH electrode is 2 years. In the sensor unit 4 having a fixed validity period in this way, the expiration date (or the first date and time of use) can be written to the sensor memory 42 when the sensor unit 4 is started to be used. The CPU 21 of the device main body 2 reads, for example, the expiration date stored in the sensor memory 42 each time the sensor unit 4 is used, compares it with the clock built in the device main body 2, and displays that the expiration date is approaching. It can be notified to the user by displaying it on 27 or the like. If the deadline has passed, the user can be warned or stopped using it.

In addition, the user can set the expiration date of calibration with the standard solution, if necessary. That is, when the user performs calibration using the standard solution, the date and time of calibration using the standard solution can be written in the sensor memory 42. As a result, the calibration date and time stored in the sensor memory 42 can be compared with the expiration date, and messages such as cautions and warnings can be displayed at any time. Further, the history information of the date and time when the calibration performed using the standard solution is performed automatically or according to the instruction of the user can be stored in the sensor memory 42. The calibration history is not limited to storing all of the calibration dates and times (at least one of the year, month, day, and time) performed up to now, but is the last calibration date and time, or a predetermined number of times before the end. It may be the calibration date and time up to.

It is also possible to store the usage time of the sensor unit 4 in the sensor memory 42. That is, the usage time is obtained by integrating the time during which the probe 3 (more specifically, the sensor unit 4) is connected to the device main body 2 while the power of the device main body 2 is turned on. According to the present invention, since each sensor unit 4 can be identified, it is possible to process and determine each integrated time even if the probe 3 (more specifically, the sensor unit 4) is replaced.

Further, the sensor memory 42 can also store the deterioration determination information of the sensor unit 4. That is, each sensor unit 4 has a theoretical generation potential. Since each sensor unit 4 has a difference, calibration is required, but basically, a potential far from the theory is not generated. Therefore, if it falls below the theoretical potential by, for example, 10%, it can be determined that the deterioration has occurred. For example, with a pH meter, two-point calibration is performed to calculate the asymmetric potential and sensitivity, but if 0 mV is ± 30 mV or more with respect to the asymmetric potential, it is abnormal, and the sensitivity is 10 with 59.16 mV as the standard. If it is less than%, it can be judged as abnormal (deterioration).

With such a configuration, since the sensor unit 4 individually stores its expiration date or calibration date and time, as well as the usage time and deterioration judgment information, the probe 3 (more specifically, the sensor unit 4) can be used. Management is achieved extremely effectively. Although the pH electrode has been described here, it can be similarly applied to an ion electrode, an electric conductivity cell, a dissolved oxygen electrode, and the like to achieve the same effect.

(IV) For example, in the case of an ion-selective electrode, when calibration is performed with an ion standard solution, the result is written in the sensor memory 42, and the calibration date and time are also written together with the calibration data. In the case of an ion electrode, since there are various ion electrodes, the type of ion measured from the model name of the read probe can be displayed or printed together with the measurement result. Therefore, several different types of probes 3 for ion measurement can be used without requiring a special switching operation of the apparatus main body 2. In the case of the ion-selective electrode, the calibration deadline and the like can be managed in the same manner as described above based on the data stored in the sensor memory 42. Further, since the ion valence can be stored in advance and the ion valence can be automatically set, it is possible to reduce forgetting to set or making a mistake.

(V) Further, for example, in a thermistor type thermometer, a correction resistor is inserted in the thermistor in order to improve the accuracy or compatibility of temperature measurement, or an element having the same characteristics is selected and used. Therefore, when the sensor unit 4 includes a thermistor (a temperature sensor for temperature compensation or a temperature sensor alone), the sensor memory 42 contains the characteristic data of the thermistor, for example, data such as a B constant, a nominal resistance value, and a temperature table. By writing, this data can be read out and calculated based on the measurement resistance value, so that highly accurate temperature measurement can be performed. The same effect can be achieved by similarly applying it to a measuring device using another resistance temperature detector electrode such as a platinum resistor instead of the thermistor electrode.

As described above, in the storage means as the identification means, in addition to the identification information, information about the sensor unit including at least one of calibration data, usage time, deterioration information, calibration history, and correction coefficient is stored. Good.

(VI) Furthermore, for information that the user does not want to change arbitrarily, such as the above-mentioned "calibration history", "first use date and time", "resistance value / temperature table", and "expiration date", use it. It is also possible to protect a person from voluntary revision. In this case, when the user operates the operation unit 26 to instruct the CPU 21 of the device main body 2 to rewrite the information based on the display on the display unit 27 of the device main body 2, it notifies that the information cannot be rewritten. Alternatively, the information can be protected by not providing the display unit 27 with the menu itself for rewriting the information. For example, the above protection can be realized by the CPU 21 of the device main body 2 executing the process according to the program stored in the main body memory 28.

The information that can be stored in the sensor memory 42 as the identification means in the above description of the present embodiment may be stored in the measurement unit memory 58 as the identification means.

[Other]
Although the present invention has been described above with reference to specific examples, the present invention is not limited to the above-mentioned examples.

For example, in the above embodiment, the analog signal acquired from the sensor unit is converted into a digital signal by the measuring circuit, and the CPU of the measuring unit calculates the measured value based on the digital signal and the calibration data (or correction value). I asked for it. On the other hand, the CPU of the main body of the apparatus may calculate and obtain the measured value based on the digital signal acquired from the measurement circuit and the calibration data (or correction value). In this case, when the calibration data (or correction value) is stored in the sensor memory or the like, the CPU of the apparatus main body performs the calibration data (or correction value) from the sensor memory or the like at the same timing as that in the above-described embodiment. Can be read and stored in the main body memory (or the storage unit of the CPU of the main body of the device) for use. Further, the CPU of the sensor unit and the CPU of the apparatus main body may be given a role of performing the calculation for the temperature compensation calculation related to the measurement and the conversion of the unit due to the change of the unit setting.

1 Measuring device 2 Device body 3 Probe 3A Probe for pH measurement (first probe)
Probe for 3B electrical conductivity measurement (second probe)
Probe for 3C dissolved oxygen measurement (second probe)
4 Sensor unit 5 Measurement unit 21 CPU of the main body of the device
22 Main unit side connector 42 Sensor memory (identification means)
51 Measurement circuit 52 Probe side connector

Claims (14)

In a measuring device having a device main body and a probe that can be attached to and detached from the device main body.
The probe refers to a sensor unit having a measurement unit according to a measurement target, a measurement circuit that converts an analog signal acquired from the sensor unit into a digital signal related to a measurement result by the sensor unit, and the device main body. It has a measuring unit and a measuring unit equipped with a probe-side connector for detachably connecting the probe.
The sensor unit is detachably attached to the measuring unit, the said sensor unit is provided with a memory in which identification information is stored,
The apparatus main body includes a first probe, which is a probe in which a first sensor unit is attached to a first measurement unit , and a second sensor unit whose measurement target is different from that of the first sensor unit. the second probe is a probe that is attached to the measurement unit of the body-side connector connectable detachably replace the probe connector, and display means, based on the digital signal obtained from the measuring unit A control unit that performs display processing for displaying the measurement result by the sensor unit by the display means is provided.
The first measurement unit includes, as the measurement circuit, a first measurement circuit that processes a signal from the first sensor unit and does not process a signal from the second sensor unit, and the second measurement unit. The unit includes, as the measurement circuit, a second measurement circuit that processes a signal from the second sensor unit and does not process a signal from the first sensor unit.
Wherein, based on the identification information read from said memory, adapted to the display processing, a first display processing conforming to measurement by the first sensor unit, the measurement by the second sensor unit A measuring device characterized in that it automatically switches to a second display process. Based on the identification information read from the memory , the control unit further changes the functions of the operating means provided in the apparatus main body to the first function suitable for the measurement by the first sensor unit and the first function. The measuring device according to claim 1, further comprising a second function suitable for measurement by the sensor unit 2 and automatically switching to. It said first, second sensor units are independently potentiometric electrodes, conductivity cell, redox current measurement electrodes, pressure sensors, is selected from the group comprising an optical sensor and temperature sensor, the first, second measurement circuit, the respective first, in response to the second sensor unit, for potentiometry, electric conductivity measurement, redox current measurement, pressure sensor, optical sensor or temperature sensor The measuring device according to claim 1 or 2, wherein the measuring circuit is the same as the measuring circuit of the above. The sensor unit includes a first inter-unit connector, the measuring unit includes a second inter-unit connector detachably connected to the first inter-unit connector, and the probe comprises the sensor unit and the measurement. The measuring device according to any one of claims 1 to 3, wherein the units are fitted and integrated by connecting the first and second inter-unit connectors. The first, at least one of the second measurement unit 1 through claim wherein a shareable measured the measuring circuit is characterized and can der Turkey replacing the different Do that the sensor unit The measuring device according to any one of 4. The measuring device according to any one of claims 1 to 5 , wherein the measuring unit is connected to the main body side connector by the probe side connector via a cable. The measuring device according to any one of claims 1 to 6 , wherein the probe is supplied with power from a power supply means provided in the device main body. The device main body has a probe presence / absence identification means for identifying the presence / absence of connection of the probe side connector to the main body side connector, and the control unit has the probe connected to the main body side connector by the probe presence / absence identification means. The measuring device according to claim 7 , wherein when it is identified that the power supply means is not supplied, the power supply from the power supply means to the probe is stopped or prohibited. The measuring device according to any one of claims 1 to 8 , wherein the device main body has a plurality of channels and has a main body side connector for each channel. The measuring device according to any one of claims 1 to 9 , wherein the identification information includes a measurement item, a model name, or a serial number. In addition to the identification information, the memory stores information about the sensor unit including at least one of calibration data, usage time, deterioration information, calibration history, correction coefficient, correction value, cell constant, and ion valence. The measuring device according to any one of claims 1 to 10, wherein the measuring device is made. The measuring device according to claim 11 , wherein the control unit controls reading / writing of information to the memory. Furthermore the control unit, before Symbol device the device printing and processing for outputting the measurement results by a printer connected to a main body or provided in the main body, and measurement toward communicably connected external device to said apparatus body The measuring device according to any one of claims 1 to 12 , wherein at least one of processes for outputting a signal relating to the result can be performed. The measurement unit is provided with another memory in which another identification information is stored.
A determination unit that determines whether or not the sensor unit attached to the measurement unit is compatible with the measurement unit based on the identification information and the other identification information on the measurement unit or the device main body. The measuring device according to any one of claims 1 to 13, wherein the measuring device is provided.

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