JPH08145930A - Odor monitor - Google Patents

Abstract

PURPOSE: To automatically correct the loss of voltage and secure the operation of an always stable sensor by detecting the line length of an elongated cord and correcting a voltage lowering part on the basis of the line length. CONSTITUTION: A fixed resistor 24 for measuring a voltage lowering part on the basis of the line length of an elongated cord EC is provided in the inside of an odor sensor 2 as a line length detection part. A resistance value of the resistor 24 is set at the same value as a composite value of a resistance value Rd of the cord EC and a resistance value of the line LN. And a voltage value for generating at both ends of the resistor 24 is taken in MPU 4, the resistance value Rd of the cord EC is calculated, correction voltage Vd on the basis of the line length of the cord EC is computed in the following: Vd=(Rd/Rh).Vh (Rh, Vh indicate the resistance value and applied voltage of a heater 2b ). The correction voltage Vd is considered, supply voltage for the heater 2b is determined and the output of a variable voltage regulator 13 is regulated. A voltage loss part due to the cord EC is thereby corrected, constant voltage can be supplied to the heater 2b , and stable operation of the sensor 2 is secured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an odor monitor for detecting and displaying an atmosphere (odor) in an environment, and more particularly to a structure in which a sensor unit and a monitor main body including a signal processing unit, a display unit, etc. are integrated or have an extension cord. The present invention relates to a portable odor monitor that can take any form of a structure that can be separated via a monitor.

[0002]

2. Description of the Related Art Conventionally, a sensor section for detecting odor and a monitor main body including a signal processing section for processing a signal from the sensor section and a display section for displaying a result thereof and the like can be separated via an extension cord. Structural odor monitors have been proposed. In such an odor monitor, a constant voltage is supplied from a constant voltage circuit via an extension cord to a heater that heats an element of a commonly used odor sensor.

[0003]

However, in the case of such a conventional odor monitor, a voltage drop occurs due to the resistance component of the lead wire forming the extension cord, and this voltage drop becomes larger as the line length becomes longer. Therefore, there is a problem that a stable heater voltage cannot be supplied, a stable operation cannot be obtained, and reliability is lowered.

The present invention has been made in order to solve such a problem, and automatically corrects the voltage loss due to the extension cord used and always supplies a constant heater voltage for stable operation. The purpose is to obtain a highly reliable odor monitor that can secure.

[0005]

The odor monitor according to the present invention includes a odor sensor for detecting an atmosphere in the environment, a signal processing section which is separated from the odor sensor, and which processes at least the detection output of the odor sensor. A monitor body including a power supply means for supplying a voltage to the sensor, an extension cord electrically connecting the odor sensor and the monitor body, a detection means for detecting the line length of the extension cord, and a voltage based on the line length of the extension cord. And a correction means for correcting the amount of fall.

Further, as the detecting means, a fixed resistor having a resistance value corresponding to at least the resistance value of the extension cord is provided in the odor sensor, and the correcting means supplies the odor sensor based on the voltage drop in the fixed resistor. The voltage is adjusted.

Further, the detecting means, when the odor sensor and the monitor main body are attached, corresponds to the shape of the plug of the odor sensor which is preset corresponding to the line lengths of a plurality of types of extension cords having different lengths. The extension code is identified, and the correction means adjusts the voltage supplied to the odor sensor based on the identification result.

Further, the detecting means determines whether or not any of a plurality of specific pins of the odor sensor plug comes into contact with a switch group provided facing the pin when the odor sensor and the monitor main body are attached. It identifies the corresponding extension code.

Further, the detecting means is such that when the odor sensor and the monitor main body are mounted, a specific pin of the odor sensor plug is
The corresponding extension cord is identified based on the resistance value when the sliding terminal of the variable resistor provided facing this pin is moved.

[0010]

According to the present invention, the line length of the extension cord is detected, and the voltage drop amount based on the line length is corrected. As a result, the voltage loss due to the extension cord that connects the odor sensor and the monitor body is automatically corrected, and stable operation can always be ensured.

Further, as the detecting means, a fixed resistor corresponding to at least the resistance value of the extension cord is provided in the odor sensor, and the voltage supplied to the odor sensor is adjusted based on the voltage drop in the fixed resistor. This allows
The extension cord can be identified simply by providing a fixed resistor equivalent to the resistance value of the extension cord in the odor sensor.
The voltage loss due to the extension cord that connects the odor sensor and the monitor body is automatically corrected, ensuring stable operation at all times.

Further, the corresponding extension cord is identified based on the shape of the plug of the odor sensor which is preset corresponding to the line lengths of a plurality of types of extension cords having different lengths,
The voltage supplied to the odor sensor is adjusted based on the identification result. As a result, the extension cord can be easily identified simply by checking the shape of the plug, and the voltage loss due to the extension cord that connects the odor sensor and the monitor body is automatically corrected, ensuring stable operation at all times. it can.

Further, the corresponding extension cord is identified by whether or not any of a plurality of specific pins of the odor sensor plug is in contact with a switch group provided facing the pin. This allows the extension cord to be easily identified simply by checking the presence or absence of multiple specific pins on the plug, and the voltage loss due to the extension cord connecting the odor sensor and the monitor body is automatically corrected and always Stable operation can be secured.

Further, a specific pin of the plug of the odor sensor identifies the corresponding extension cord based on the resistance value when the sliding terminal of the variable resistor provided facing this pin is moved. This makes it easy to identify the extension cord by simply changing the length of a specific pin on the plug, and the voltage loss due to the extension cord that connects the odor sensor and the monitor body is automatically corrected and always stable. It is possible to secure the operation that was performed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.
In the figure, 1 is a portable odor monitor, and 2 is an odor sensor made of, for example, a SnO ₂ semiconductor thin film for detecting an atmosphere in the environment, for example, a reducing atmosphere (gas) or an oxidizing atmosphere (gas). The odor sensor 2 has a resistance value that changes in a reducing atmosphere and a resistance value that changes in the opposite direction to the reducing atmosphere with respect to an oxidizing atmosphere. For example, odors such as TMA and nicotine, riboglucosan, and the like. Burnt odor, that is, the resistance value is reduced with high sensitivity to reducing gas and the like, while on the other hand, about 0.03 ppm is also detected with high sensitivity to oxidizing gas such as ozone and NO _2. The resistance value increases. Further, the odor sensor 2 standardizes the output, determines a reference gas or the like, and calibrates it.
Output of odor sensor 2 in nicotine 10ppm +1.0
Output of odor sensor 2 in V and ozone 1ppm is -1.0V
It has been. 3 is a sensor interface connected to the odor sensor 2, 4 is this sensor interface 3
It is a microprocessor unit (hereinafter, referred to as MPU) as a correction unit that is supplied with the detection output of the odor sensor 2 via the.

The MPU 4 has an arithmetic unit 41 for performing arithmetic processing.
And the odor sensor 2 via the sensor interface 3.
3 to 5 which will be described later and are connected to an A / D converter 42 for A / D converting the detection output supplied from
It has a ROM 43 in which the programs of the flowchart shown in FIG. 1 are stored in advance, a timer 44 connected to the arithmetic unit 41, and a RAM 45 interconnected with the arithmetic unit 41 and used in the arithmetic processing.

The RAM 45 stores, for example, as shown in FIG. 2, a work area 45a, a display area 45b for storing contents such as displays and alarms, and contents regarding the setting state of the odor monitor by key operation or the like. A setting area 45c,
And a data area 45d for storing fixed data and the like used for conversion of the odor index. As an example, the display area 4
Reference numeral 5b denotes an odor index N which will be described later, a correction resistance value Z _nc in the environment, a peak hold lower limit value PHN _L , a peak hold upper limit value PHN _H , a use state display on a monitor, a bar graph content, and a buzzer. ON / OFF / intermittent control, error content, display of odor index calculation method such as AB CAL, etc. are stored. Also, setting area 45c stores OFF / ON status of absolute switching function, auto calibration setting function. 0N / 0FF status, peak hold value display function
Various setting states such as 0FF / ON state and OFF / ON state of range switching function are stored, and further, in the data area 45d,
The same data as that of the EEPROM 7 described later is stored.

Further, the MPU 4 A / D-converts the information for monitoring the state of the voltage regulator, which will be described later, and supplies it to the arithmetic unit 41, and the output from the arithmetic unit 41 is D A / A conversion unit 47 for A / A conversion and output to the outside, and data from the arithmetic unit 41 after serial-parallel conversion to an external device, such as a personal computer (not shown), and vice versa. Data is converted into parallel-serial data and input to the arithmetic unit 41, which is a so-called general-purpose asynchronous receiver / transducer (UART: universal asynchronous receiver / trans).
mitter) serial-parallel and parallel-serial converter 48
And further.

Reference numeral 5 denotes a liquid crystal display (hereinafter referred to as LCD) driver connected to the arithmetic unit 41, and 6 denotes an LCD driven by the LCD driver 5 to display various information. Reference numeral 7 denotes an EEPROM interconnected with the arithmetic unit 41. The EEPROM 7 has, for example, the saturation resistance value Z _m of the odor sensor 2 as fixed data necessary for calculating the odor index, a so-called clean state in which there is no odor. resistance Z _ns 0 odor sensor 2 in air (STP), the resistance value Z _ns odor sensor 2 in the reference odor, the load resistance R
Further, the measured power supply voltage V and the like are stored, and as other numerical data, for example, an alarm level value ARM and the like are stored.

Reference numeral 8 denotes an operation unit having keys corresponding to a plurality of functions connected to the calculation unit 41.
For at least ON / OFF key to turn on / off the power, and to turn on / off the auto calibration setting function.
AUTO CAL key, ON / OFF of peak hold value display function P / V HOLD key, data setting function, data selection (rotation so that the value increases) △ key, data setting function, data selection ( Rotate so that the value becomes smaller) ▽ key, ON / OFF of data setting function, ALARM SET key, ON / OFF of absolute switching function
AB CAL key for OFF and ON / OF for range switching function
The RANGE key etc. which perform F are provided. In addition, AUTO CAL
The key activates the fixed data input function in combination with the P / V HOLD key during the data setting function.

Reference numeral 9 is connected to the arithmetic unit 41, and a buzzer for issuing an alarm when the odor index exceeds a predetermined value or the power supply voltage falls below a predetermined value, and 10 is connected to the D / A conversion unit 47. An output buffer for outputting information about the odor index to the outside, 11 is a power supply circuit, 12 is connected to the power supply circuit 11, and each internal circuit and the element 2a of the odor sensor 2 (see FIG. 1).
3, FIG. 15 and FIG. 17), which is a voltage regulator that supplies a stabilized power supply voltage. As the voltage regulator 12, for example, a constant voltage circuit is used. Reference numeral 13 is connected to the power supply circuit 11 and is connected to the heater 2b (see FIG.
3, FIG. 15 and FIG. 17) is a variable voltage regulator as a power supply means for supplying a stabilized voltage. As will be described later, the variable voltage regulator 13 also functions as a correction unit alone or together with the MPU 4.

Reference numeral 14 denotes an output terminal connected to the series-parallel and parallel-series converter 48.
For example, a personal computer (not shown) is connected via an RS232C level converter (not shown). Reference numerals 15 and 16 are output terminals connected to the output buffer 10. The output terminals 15 and 16 are respectively on the + side (reducing atmosphere).
And the odor index on the − side (oxidizing atmosphere) is, for example, 0 to 5
It is output by a voltage between V. At this time, since the odor index is one, it is output by any voltage. Reference numeral 17 is an output terminal connected to the output side of the sensor interface 3, and raw data is directly supplied to the output terminal 17 from the odor sensor 2 via the sensor interface 3. These output terminals 1
A data logger, a recorder and the like (not shown) are connected to 5 to 17, for example. 18 is a power supply circuit 1
1 is a power supply terminal connected to an external commercial power supply (not shown) when operating as an AC adapter. The output terminals 15 and 16 have a reducing atmosphere of, for example, 0 to 5 V based on the odor index in the clean air.
In addition, the output terminal 16 has an oxidizing atmosphere of, for example, 0 to
The voltage is output at 5 V, and the absolute value of the odor index is output as a voltage. Therefore, while the output terminal 15 is outputting, the output terminal 16 is 0 V, the output terminal 16
Is output, the output terminal 15 becomes 0V. Reference numeral 20 denotes a line length detecting unit as a detecting means for detecting the line length of the extension cord EC (see FIGS. 13, 15 and 17).
Based on the detection of the line length of the extension cord EC, the voltage loss is corrected by the extension cord EC as described later.

Next, the operation will be described. First, the overall operation will be schematically described with reference to FIG. In the following description, the determination operation is entirely controlled by the calculation unit 41. When the power is turned on, first, in step S1, initial settings such as reading data from the EEPROM 7 and storing it in the RAM 45 are performed as will be described later. Next, in step S2, as warm-up, a predetermined time, for example, 3 minutes, stands by until the odor sensor 2 stabilizes. Data can be set in the RAM 45 by operating the keys of the operation unit 8 even during the standby for 3 minutes. That is, in this 3-minute standby (STANDBY) mode, in step S3,
It is determined whether or not there is a setting input, and if not, step S2
And wait for 3 minutes, if any, in step S4,
A setting process for the RAM 45, which will be described later, is performed.
During this standby mode, the characters "STANDBY" are displayed on the LCD 6 in a predetermined area of the display screen, for example, in the upper left area.

On the other hand, when 3 minutes have passed in step S2, the ready (READY) mode is entered and the odor measurement is started. That is, first, in step S5, data relating to ON / OFF setting states such as a peak hold value display function, a calibration setting function, and an absolute switching function is read from the RAM 45 as described later. Then, in step S6, the output of the odor sensor 2 is read and sampled through the A / D converter 42 and the sensor interface 3, and necessary fixed data is EEPRO.
It is read from M7 and, as will be described later, step S7.
In, the odor index is calculated. During the ready mode, the LCD 6 displays a character "READY" in a predetermined area of the display screen, for example, in the upper left area, and a bar related to the odor index displayed in the predetermined area of the display screen, for example, the central portion. 0 for graph display and digital display
It is said.

This odor index uses the reference resistance at the intensity of the reference odor to standardize the resistance that changes depending on the state of the object to be detected, for example, the odor pressure.
It is calculated as follows using the above-mentioned fixed data stored in the ROM 7 and the output value (measurement voltage) detected by the odor sensor 2. First, the reference resistance r _ref is calculated by the following equation using fixed data.

R _ref = (Z _ns −Z _m ) (Z _ns 0 −Z _m ) / (Z _ns 0 −Z _ns ) (1)

Then, the measured voltage E detected by the odor sensor 2 is converted into a resistance value by the following equation, and this is set as a measured resistance value Z _n .

Z _n = R (V−E) / E (2)

Then, the measured resistance value Z _n is converted into the odor index N by the following equation.

[0030] _{N = r ref / r n =} r ref (Z0-Z n) / (Z n -Z m) (Z0-Z m) (3)

[0031] In the above (3), r _n is the resistance that varies with odor pressure, Z0 is the initial resistance of the odor sensor 2, as the Z0, as will be described later, as a state no smell When calculating the odor index based on the resistance value in the clean air, the resistance value Z _ns 0 in the clean air is used. When calculating the odor index based on the resistance value in the atmosphere of the measurement environment, The medium correction resistance value Z _nc is used.

When the calculation of the odor index is completed in this way, in step S8 the calculated odor index is discriminated to perform necessary display, warning, output to the outside and the like.
Then, the above operation is repeated after a waiting time according to the value set in the timer 44. That is, in step S9, it is determined again whether or not there is a setting input.
In step S10, the same setting process as in step S4 described above is performed, and the process returns to step S9 to repeat the same operation as described above. If not, the process returns to step S9 to stand by, and if it is necessary to enter, the process returns to step S5 to repeat the above operation. This sampling operation is performed once per second, for example. This completes the entire operation. As described above, in the present embodiment, the odor intensity in the environment is calculated as the odor index by using the above formula, but the odor intensity based on the resistance change from the initial resistance of a general element is calculated. You may make it use the method of doing.

Next, each step (routine) of FIG. 3 will be described in detail. First, with reference to FIG. 4, the operation of the “initial setting” in step S1 will be described. After turning on the power, in step S21, after confirming each part necessary for the operation of the MPU 4, in step S22, EEPRO
The preset data is read from M7.
Then, in step S23, it is determined whether or not the data is normally read out, and if the data is normally read out, in step S24, those data are stored in the RAM.
45 in the data area 45d, and thereafter during operation,
The data will be read from the RAM 45. In the determination of the data in step S23, it is checked whether the numerical value of the data is within the predetermined range. If the numerical value is outside the predetermined range, it is determined that the data is incorrect.

On the other hand, if the data is not normally read in step S23, the process proceeds to step S25. As a case where the data is not normally read out, for example, originally EE
There is a case where abnormal data is erroneously stored in the PROM 7 or an error occurs when reading the data and the data cannot be read. Alternatively, EE
When reading data from the PROM 7, the data may not be set in the EEPROM 7 in the first place.
In particular, at the time of startup immediately after manufacturing, of course, no data is set. In such a case, since normal data cannot be read in step S23, the LCD driver 5 drives the LCD 6 to display an error in step S25. To confirm these data, for example, the total value of the data to be read is stored in the EEPROM 7, and the total value of the read data and the EEPROM 7 are stored.
Abnormality of data may be determined by comparing with the total value in the above.

Then, in step S26, the ROM
So-called default data is read from 43, the read default data is stored in the EEPROM 7 in step S27, and stored in the RAM 45 in step S28. Thereafter, an operation using this default data is performed as an operation of the odor monitor. . Note that the default data is read all at once in the flowchart of FIG. 4, but the presence or absence of the setting is checked for each individual data, and the default data is read only for those that do not exist. Good. In addition, as this default data, EEPR
Data corresponding to the data stored in the OM 7 is stored in the ROM 43 in advance as default data. This default data may also be generated by software.

By performing such an initial setting operation as the processing when the power is turned on, there are the following advantages. That is, when abnormal data is stored in the EEPROM 7 by mistake, the sensor characteristics are calibrated with such data, or an abnormal value is obtained when the displayed odor index is set to a correct value by calculation. When the data is read from the EEPROM 7 and an error occurs when the data is read from the EEPROM 7, the odor monitor does not function in the same manner. In such a case, however, the typical odor monitor is as described above. By setting various characteristic data in the ROM 43 in advance and using these data as default data when an abnormality occurs, the odor monitor can be operated normally and the reliability of the device can be improved.

Further, even if the above-mentioned characteristic data is not set in the EEPROM 7, the R with a certain degree of reliability is obtained.
The odor index can be displayed by the data from the OM43. Then, such default data is read from the ROM 43 to read the EEPROM 7 and the RAM 4
By also storing it in 5, in the next cycle, R
The procedure of reading this default data from the OM 43 can be omitted.

Next, referring to FIGS. 5 to 7, step S
The operation of the "setting process" of 4 (S10) will be described.
First, the all calibration setting function will be described. This all-calibration setting function is a function of correcting the initial resistance value Z0 of the odor index. In step S31, it is determined whether or not the AUTO CAL key for turning ON / OFF the auto-calibration setting function of the operation unit 8 is pressed, and if it is pressed, the setting area 45c of the RAM 45 is referred to in step S32. The automatic calibration setting function is in the ON state or the OFF state, and if it is in the OFF state, in step S33,
ON is set in the setting area 45c of the RAM 45.

Then, in step S34, the value of the measured resistance value Z _n is corrected and set as the corrected resistance value Z _nc in the environment in the display area 45b of the RAM 45, and then in step S35.
In, the time t of the timer 44 is set to 0. This correction is performed every predetermined time, for example, every 30 minutes. Step S
If the auto-calibration setting function is in the ON state by referring to the setting area 45c of the RAM 45 in 32, the OF is set in the setting area 45c of the RAM 45 in step S36.
F is set and the measured resistance value Z _n is not corrected. The current state at this time is displayed in a predetermined area of the display screen of the LCD 6, for example, in the upper right of the uppermost portion, and the ON state is "AUTO CAL", O.
The FF status is displayed as "AUTO OFF".

On the other hand, if the AUTO CAL key is not pressed in step S31, the operation unit 8 is operated in step S37.
It is determined whether or not the AB CAL key for turning ON / OFF the absolute switching function of is pressed. If it is pressed, in step S38, the absolute switching function is turned ON by referring to the setting area 45c of the RAM 45.
It is determined whether it is the F state, and if it is the OFF state, step S3.
9, the setting area 45c of the RAM 45 is set to ON, and if it is in the ON state, RA is set in step S40.
OFF is set in the setting area 45c of M45.

As will be described later, the absolute switching function calculates the odor index with the initial resistance value Z 0 as Z _{n s} 0 and switches the display range of the bar graph on the display screen of the LCD 6 and the peak hold display format. Then, it is turned off at startup. When the absolute switching function is changed from the OFF state to the ON state as described above, the auto-calibration setting function state is saved and the absolute switching function is set to the OFF state.

Then, the absolute switching function is turned on.
When the N state is turned off, the auto calibration setting function state is returned to the saved state. That is, the auto-calibration setting function is linked to the absolute switching function, and has priority over the auto-calibration setting function when the absolute switching function is turned on. Therefore, in the setting processing routine, if there is any input operation, the setting processing operation is started.
If the input is the pressing of the AB CAL key, the ON / OFF state of the absolute switching function is switched, but if there is another input, other setting processing is performed. Here, as an example, the case where the setting process of the automatic calibration setting function is performed is shown.

On the other hand, if the AB CAL key is not pressed in step S37, other setting processing is started. here,
For example, a case of entering a peak hold value display function that is a function of displaying the upper and lower limit values of the odor index will be described.
In step S41, it is determined whether or not the P / V HOLD key for turning ON / OFF the peak hold value display function of the operation unit 8 has been pressed. If so, in step S42, the setting area 45c of the RAM 45 is set. Refer to it to determine whether the peak hall value display function is ON or OFF,
If it is in the F state, in step S43 the RAM 45
ON is set in the setting area 45c of.

Then, in step S44, the currently detected odor index N is set to the peak hold upper limit value PHN.
_It is stored in the display area 45b of the RAM 45 as _H , and in step S45, the currently detected odor index N is stored in the display area 45b of the RAM 45 as the peak hold lower limit value PHN _L. Also, in step S42, R
If the peak hold value display function is ON with reference to the setting area 45c of the AM 45, OFF is set in the setting area 45c of the RAM 45 in step S46.

As will be described later, this peak hold value has an odor index obtained at the next time when it changes from the OFF state to the ON state as an initial value, and the odor index is calculated until the OFF state thereafter. It is compared and updated each time it is performed. The peak hold value display function is turned off at startup. If the peak hold value display function is ON, the peak hold value is
It is displayed in a predetermined area of the D6 display screen, for example, in the lower part.
Nothing is displayed in the F state. At that time, when the peak hold value is negative, a minus sign is added before the numerical value, and when the peak hold value is positive, nothing is displayed.

On the other hand, if the P / V HOLD key is not pressed in step S41, another setting process, for example, the range switching function is started. This range switching function is available on the LCD 6
This is a function to switch the full-scale value of the bar graph displayed on the display screen of. In step S47, it is determined whether or not the RANGE key for turning ON / OFF the range switching function of the operation unit 8 has been pressed. If so, in step S48, the range switching is performed by referring to the setting area 45c of the RAM 45. It is determined whether the function is in the ON state or the OFF state.
OFF is set in the setting area 45c of the AM 45, and if it is in the OFF state, ON is set in the setting area 45c of the RAM 45 in step S50. At that time, if the range switching function is in the ON state, the scale value of the bar graph on the display screen of the LCD 6 displays, for example, 0 to 0.6, and O
In the FF state, 0 to 3 are displayed.
Then, this range switching function is turned on at startup.

If the RANGE key is not pressed in step S47, the data set function is entered. This data set function is a function for setting various data necessary for the odor monitor. This data set function has two types: alarm setting mode and fixed data setting mode.
In the alarm setting mode, set the alarm level value of the alarm level alarm function, and in the fixed data setting mode,
Set the fixed data used in the calculation of odor index.

First, the case of changing and setting the alarm level value of the alarm level warning function will be described with reference to FIG. In step S51, it is determined whether or not the ALARM SET key for turning ON / OFF the data setting function of the operation unit 8 is pressed, and if it is pressed, in step S52,
The alarm level value ARM of the fixed data stored in the EEPROM 7 is digitally displayed as "ARM" indicating the input of the alarm level value in a predetermined area, for example, the lower part of the display screen of the LCD 6. Further, the input cursor (_) indicating the current input position is designed to point to the uppermost digit of the integer part of the digitally displayed current value.

Then, in step S53, it is determined whether or not both the AUTO CAL key and the P / V HOLD key of the operation unit 8 are pressed. If they are not pressed, step S5
Go to 4. That is, here, the alarm level value can only be changed immediately after the ALARM SET key is pressed. When changing the displayed value of the alarm level value ARM, the cursor (_) is first displayed in the maximum digit portion of the numerical values displayed on the LCD 6, and the numerical value can be changed only at the position of the cursor. . To change this numerical value, the △ key and ▽ key for selecting the data of the operation unit 8 are used.

That is, in step S54, P / V
If the HOLD key is not pressed, by pressing the △ key in step S55, the number of alarm level values displayed on the LCD 6 is incremented by 1 in step S55, and similarly, by pressing the ▽ key in step S57. , In step S58, the display number of the alarm level value displayed on the LCD 6 is decremented by 1. As a result, the number of the digit at the cursor is scrolled between 0 and 9, and only that digit can be changed.

The P / V HOLD key is used to move the digit of the numerical value. Therefore, when changing the number of each digit,
After changing the maximum digit using the △ and ▽ keys as described above, press the P / V HOLD key to move the cursor one digit. That is, in step S54, P / V HO
When the LD key is pressed and it is confirmed in step S59 that it is not the last digit, the input digit is moved in step S60. Then, similarly, the numerical value of the next digit is changed.

Repeat this to change to the last digit and change to P /
When the V HOLD key is pressed, the cursor naturally returns to the maximum digit, but at that time, that is, when it is confirmed that it is the last digit in step S59, in step S61, the alarm level value which is the changed data. EEP to ARM
It is stored (written) in a predetermined area of the ROM 7. Note that this data is stored in the EEPROM 7 at the same time as the RAM 4
The data area 45d is stored in the RAM 45, but may be stored in the RAM 45 at the end of the entire setting process. Then, by pressing the ALARM SET key in step S62,
Although the setting processing routine is ended, no data is written in this operation regardless of the processing state. If the ALARM SET key is not pressed in step S51, other setting processing is performed in step S63.

When changing the fixed data in the EEPROM 7, after pressing the ALARM SET key, AU is displayed while the numerical value of the alarm level value ARM is displayed.
If you press the P / V HOLD key while pressing the TO CAL key, you can change the display of all fixed data. next,
A case of changing and setting the fixed data will be described with reference to FIG. In step S53 (FIG. 6), the AUTO CAL of the operation unit 8
When it is confirmed that both the key and the P / V HOLD key are pressed, the first fixed data among the fixed data stored in the EEPROM 7 is read out and displayed on the LCD 6 in step S64.

[0054] fixed data stored in EEPROM7 is, as described above, the saturation resistance Z _m, the resistance value Z _ns 0 of dry air (STP), the resistance value Z _ns in the reference odor,
The load resistance value R, the measured power supply voltage V, and the like, and the alarm level value ARM and the like are also stored as other numerical data. At first, for example, the saturation resistance value Z
_m is displayed, below, the resistance value Z _ns 0 of dry air (STP), the resistance value Z _ns in the reference odor, are displayed in order of the load resistance R and the measurement power supply voltage V. In that case, for example, the saturation resistance value Z _m is displayed as follows. Z _m □□□□□ 0 1 2 3 At that time, the cursor is displayed at the position of "Z" which is the first character in the display, and when the P / V HOLD key is pressed, the cursor changes to that position. It shifts by one character. And
When the numeral portion comes, as in the case of changing the alarm level value described above, the Δ key and the ∇ key are used to scroll between 0 and 9, and the digit portion can be changed.

That is, in step S65, P / V
If the HOLD key has not been pressed, after confirming the pressing of the Δ key in step S66, it is determined in step S67 whether the digit content is a character or a numeric value. If the digit content is a numeric value, it is displayed on the LCD 6 in step S68, for example. Saturation resistance value Z
Increment the display number of _m by 1, and if it is a character,
In step S69, the previous fixed data stored in the EEPROM 7 is read out and displayed on the LCD 6.
Similarly, after confirming the depression of the ▽ key in step S70, it is determined in step S71 whether the digit content is a character or a number. If the digit content is a number, the saturation resistance value Z _m displayed on the LCD 6 is displayed in step S72. Decrement the number by 1, and if it is a character, in step S73, EE
The next fixed data stored in the PROM 7 is read out and displayed on the LCD 6. As a result, the number of the digit at the cursor is scrolled between 0 and 9, and only that digit can be changed.

In this case as well, in order to move the digit of the numerical value,
Use the P / V HOLD key. Therefore, when changing the numeral of each digit, after changing the numeral of the maximum digit by using the △ and ▽ keys as described above, the cursor is moved by one digit by pressing the P / V HOLD key. That is, in step S65, press the P / V HOLD key, and in step S74,
If it is confirmed that it is not the last digit, the input digit is moved in step S75. Then, similarly, the numerical value of the next digit is changed.

Repeat this to change the last digit to P /
When the V HOLD key is pressed, the cursor naturally returns to the maximum digit, but at that time, that is, when it is confirmed that it is the last digit in step S74, in step S76, the saturated resistance value that is the changed data Z _m to EEPROM 7
Is stored (written) in a predetermined area. In this case also, the data is stored in the EEPROM at the same time as the RAM4.
5 data area 45d. Then, by pressing the ALARM SET key in step S77, the setting processing routine is ended, but this operation does not write data regardless of the processing state.

As a function of each of the Δ key and the ▽ key, the display contents are changed by operating both keys in the above-mentioned display state. That is, as described above, when the ∇ key is pressed in the character portion of the display content, the displayed content changes from the saturation resistance value Z _m to the next resistance value Z _ns 0 in dry air (standard state). Then, similarly to the above, the numerical value can be changed by the P / V HOLD key, the Δ key and the ▽ key, and the numerical value can be stored in the EEPROM 7.

By having such a data setting function, there are the following advantages. That is, the current EEPR
The data stored in the OM7 can be displayed, and the numerical values of the data stored in the EEPROM7 can be updated by the up / down key, that is, the △ and ▽ keys, and the shift key, that is, the P / V HOLD key. Further, since it is possible to scroll the data to be displayed by operating the up and down keys in the character portion, the device can be normally operated in the field.

That is, substantially, if there is an odor sensor with data, the data can be directly input to this odor monitor, and the data of the odor sensor currently input can be read. Therefore, it is no longer necessary to bring it back to the factory or the like to calibrate it in order to replace the odor sensor as in the conventional method, or to calibrate the odor sensor in a circuit manner, a resistor, etc., on the circuit board at the same time as the odor sensor. You don't have to install it,
Work related to calibration and the like is simple and efficient monitoring is possible.

Next, referring to FIG. 8, the operation of "data reading" in step S5 will be described. In the entire flow, before the sampling of the output of the odor sensor 2, the setting for calculating the odor index as the setting state of the odor monitor is discriminated from the RAM 45 in this data reading routine and set. That is, before sampling the output of the odor sensor 2 to calculate the odor index, whether the resistance value Z _ns 0 in the dry air is used as the initial resistance value Z 0 used in the equation (3), It is determined whether to use the corrected resistance value Z _nc .

Therefore, first, in step S81,
The setting area 45c of the RAM 45 is referred to. Then, in step S82, it is determined whether or not the AB CAL key for turning ON / OFF the absolute switching function of the operation unit 8 is pressed, and if it is pressed, in step S83,
The resistance value Z _ns 0 in the clean air is set to the initial resistance value Z 0 stored in the data area 45d of the RAM 45. When using the resistance value Z _ns 0 in this clean air, the value is
The odor index will be calculated based on the resistance value in dry air in a state where there is no odor. Therefore, it is effective in discriminating whether the atmosphere of the measurement environment is oxidizing or reducing, and in obtaining the absolute odor index of the measurement environment.

On the other hand, in step S82, the operation unit 8
If the AB CAL key for turning ON / OFF the absolute switching function of is not pressed, R is selected in step S84.
The corrected resistance value Z _{n c} in the environment is set to the initial resistance value Z 0 stored in the display area 45b of the AM 45. When the resistance value Z _nc of the corrected resistance value in this environment is used, the odor index is calculated with reference to the resistance value of the atmosphere of the measurement environment. Corrected resistance value Z in this environment
_{For nc} , the resistance value due to the atmosphere is set by the auto calibration setting function, and by setting the auto calibration setting function to the ON state,
For example, it is updated every 30 minutes.

In this data reading routine, the auto calibration setting function is turned on and off.
The state is not referenced because the absolute switching function has priority over the auto-calibration setting function. For the auto-calibration setting function, the correction resistance value Z _nc in the environment is updated in the routine of the determination process described later. It is enough if done.

By having such an absolute switching function, there are the following advantages. That is,
It is possible to capture environmental changes including environmental gases other than those to be measured, and the influence of all other environmental gases can be measured using the output of the odor sensor in the atmosphere of clean air (standard state) as a reference value. In addition, the sensor element used in the odor sensor generally produces + output in a reducing atmosphere such as odor and − output in an oxidizing atmosphere, but here, a single odor monitor is used as a reference for clean air. Can be displayed, and the absolute status of the environmental atmosphere can be displayed, and an inexpensive and versatile odor monitor can be obtained.

Next, with reference to FIG. 9, the operation of the "smell index conversion" in step S7 will be described. The conversion of this odor index uses the above equations (1) to (3). Since (1) above is a calculated value based on fixed data, it is calculated in the initialization routine and stored in a predetermined position in the data area 45d of the RAM 45. Therefore, in step S91, according to the above equation (2),
The voltage E taken as the output of the odor sensor 2 is converted into the measured resistance value Z _n . Then, in step S92, the measured resistance value Z _n is converted into the odor index N according to the above equation (3). In the above data reading routine, it is determined whether the numerical value used for the initial resistance value Z0 of the equation (3) is the resistance value Z _ns 0 in clean air or the correction resistance value Z _nc in the environment is used. However, the numerical value setting may be performed during the odor index conversion in step S7.

Next, referring to FIG. 10, the operation of the "discrimination process" in step S8 will be described. The routine of this determination processing is a portion that, when the processing of sampling the output of the odor sensor 2 to calculate the odor index is completed, performs the processing using the odor index and performs display, warning, output, and the like. First, in step S101, the numerical value of the odor index N calculated in step S7 is stored in the display area 45b of the RAM 45, and in step S102, the bar content related to the numerical value of the odor index N is also stored in the RAM 45.
In the display area 45b of the RAM 45, and the setting area 45c of the RAM 45 is referred to in step S103. And
In step S104, it is determined whether or not the P / V HOLD key for turning ON / OFF the peak hold value display function of the operation unit 8 is pressed. If the P / V HOLD key is pressed, the display area 45b of the RAM 45 is displayed in step S105. Stored peak hold value PHN (peak hold lower limit value PHN
_L , peak hold upper limit value PHN _H ) are read.

[0068] Then, at step S106, it compares the odor index N peak hold upper limit PHN _H, when the odor index N is lower than the peak-hold upper limit PHN _H further in step S107, odor index N peak hold lower-limit The value PHN _H is compared, and when the odor index N exceeds the peak hold lower limit value PHN _L , that is, the odor index N is the peak hold upper limit value PH.
When it is within the range between N _H and the peak hold lower limit value PHN _L , the peak hold value PHN at that time is stored in the display area 45 b of the RAM 45 without updating anything.

On the other hand, when the odor index N exceeds the peak hold upper limit value PHN _H in step S106, and when the odor index N falls below the peak hold lower limit value PHN _L in step S107, that is, the odor index N reaches the peak hold upper limit. If the value PHN _H is out of the range of the peak hold lower limit value PHN _L , the peak hold value is updated in steps S109 and S110, and the updated peak hold value PHN is set to R.
It is stored in the display area 45b of the AM 45.

With the peak hold upper limit value PHN _H and the peak hold lower limit value PHN _L , the odor index N is detected not only in the plus direction but also in the minus direction. It will be held in comparison. Therefore, the maximum value can be maintained not only in the reducing atmosphere in the environment but also in the oxidizing atmosphere. Then, after performing other processing according to the set state, the display by the LCD 6 and the alarm by the buzzer 9 are performed according to the contents of the display area 45b of the RAM 45.

Here, as another process, for example, in step S111, an alarm level warning function is performed as an alarm process. This is a function of issuing an alarm by the buzzer 9 when the odor index N exceeds the set alarm level. At this time, when the alarm is issued, the buzzer 9 continuously sounds. When the odor index N is restored below the alarm level, the buzzer 9 stops ringing. In addition, by pressing a specific key, for example, the ∇ key during the alarm, the buzzer 9 stops ringing, and if the state where the odor index N exceeds the alarm level continues thereafter, the buzzer 9 does not ring. Further, after the odor index N once recovers below the alarm level, if the odor index N exceeds the alarm level again, the buzzer 9 sounds.

In step S112, it is determined whether or not data logging is possible, that is, data logging from an external personal computer, for example, to the series-parallel and parallel-serial converter 48 connected to the output terminal 14. It is determined whether or not the flag indicating the request of (1) is transmitted, and if there is a request for data logging, step S113.
In, data logging processing, that is, the function of data logging is executed. This data logging function is a function to perform various settings necessary for data logging. Examples of these various settings include data file name setting to set the file name to be logged on the personal computer side and data request to the odor monitor. Sampling cycle setting for setting the cycle for performing the RS232 requesting data to the odor monitor for each cycle set by the sampling cycle setting
There is a data file or the like for writing the C input or the odor index input by the RS232C input in a file in a predetermined format, for example, the CV format.

In step S114, the battery check process, that is, the battery alarm function is executed. This battery alarm function monitors the output of the power supply circuit 11, for example, the battery voltage via the A / D converter 46,
It is a function to issue an alarm when the value falls below the specified value. This function is designed to work in both the standby mode and the ready mode. At the time of notification, L
In the predetermined area of the CD6 display screen, for example in the upper left corner, "LAW BA
"T." is displayed, and the buzzer 9 sounds intermittently. A
When the battery voltage is restored to the specified value by the C adapter, the display of "LAW BAT." On the display screen of the LCD 6 is erased and the buzzer 9 stops ringing. Further, by pressing a specific key, for example, the ∇ key during the alarm, the ringing of the buzzer 9 is stopped, and the ringing of the buzzer 9 is not performed if the state where the battery voltage is lower than the specified value continues after that. Also,
After the battery voltage is once restored to the specified value, when the battery voltage is lowered again, the buzzer 9 sounds. Further, in step S130, deterioration of the elements of the odor sensor 2 due to aging (moving average deterioration detection) is detected as described later.

Next, in step S115, the RAM
It is determined whether the auto-calibration setting function is ON or OFF by referring to the setting area 45c
If it is in the state, the coefficient t related to the automatic calibration is incremented by 1 in step S116. This coefficient t is incremented by 1 each time the odor index N is calculated from the position on the flow, and is basically 1
Since it is calculated every second, it will be updated every other second. Then, in step S117, the coefficient t is compared with the predetermined number T. The predetermined number T is a numerical value for measuring, for example, 30 minutes, and since the coefficient t is every 1 second,
If T = 1800, 30 minutes will be measured. Therefore, when the coefficient t is not equal to the predetermined number T in step S117, that is, when 30 minutes have not elapsed,
In step S118, the display area 45 of the RAM 45
The content of b, that is, the resistance value Z _n measured 30 minutes before is L
Display on CD6.

When the coefficient t becomes equal to the predetermined number T in step S117, that is, when it reaches 30 minutes, it is determined in step S119 whether or not the odor index N exceeds a predetermined value, for example, 0.3. , The odor index N is 0.3
If it exceeds, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when the odor is detected, the resistance value Z _n is not updated and the resistance value Z _n measured 30 minutes before is displayed on the LCD 6.

On the other hand, in step S119, if the odor index N does not exceed a predetermined value, for example, 0.3, that is, if odor is not detected, in step S120, the measured resistance value Z _n at that time is measured in the environment. The corrected resistance value Z _nc is stored in the display area 45b of the RAM 45.
Then, in step S121, the coefficient t is set to 0,
In step S118, the display area 45 of the RAM 45 is displayed.
The content of b, that is, the stored resistance value Z _n is displayed on the LCD.
Display in 6. If the auto-calibration setting function is OFF in step S115 with reference to the setting area 45c of the RAM 45, immediately step S118 is performed.
Proceed to, and display the contents of the display area 45b of the RAM 45 on the LCD.
Display in 6.

In this auto-calibration setting function, in the conventional gas sensor or the like, the changing direction of the resistance value Z _n is fixed to the lower side, so that the correction of the reference value is limited to the lower side from the first reference value. However, in the present embodiment, since both the oxidizing and reducing atmospheres are measured, the reference value is corrected regardless of the initial reference value and its changing direction. In this auto-calibration setting function, the reference value is corrected with the value at the break point of the predetermined period.
If it is every minute, a value representative of 30-minute data, for example, an average value, a median value, or the lowest value thereof may be used, and further, a processed value or a representative value for the updated value may be used. You may use the plus alpha of a value or the value of 80%.

By having such a peak hold value display function, there are the following advantages. That is, the peak hold value can be displayed not only for the positive maximum value and the minimum value but also for the negative maximum value and the minimum value, and in particular, there may be an oxidizing atmosphere that changes to the negative side. The peak hold value can be easily and accurately displayed even under various environments.

Further, by having the automatic calibration setting function, there are the following advantages. In other words, it becomes possible to automatically correct the odor index, and it is necessary to adjust the zero point with the volume to correct the odor sensor as in the past, or to configure clean air and standard gas in the test box. Therefore, correction can be performed easily, efficiently, and quickly, and the device can always be normally operated.

11 and 12 are flowcharts showing other embodiments for updating the correction resistance value Z _nc in the environment. FIG. 11 shows the case where the average value of a predetermined period is taken.
Is the case of taking the most recent value. First, in FIG. 11, in step S115, it is determined whether the auto-calibration setting function is in the ON state or the OFF state by referring to the setting area 45c of the RAM 45.
At 116, the coefficient t associated with autocalibration is incremented by one. Then, in step S122, the total value ΣZ _n of the measured resistance values Z _n is calculated every time the odor index N is calculated, and the work area 45a of the RAM 45 is calculated.
To be stored. Next, in step S117, the coefficient t is compared with the predetermined number T, and when the coefficient t is not equal to the predetermined number T, that is, when 30 minutes have not elapsed, in step S118, the contents of the display area 45b of the RAM 45, That is, the resistance value Z _n measured 30 minutes before is displayed on the LCD 6
To be displayed.

On the other hand, when the coefficient t becomes equal to the predetermined number T in step S117, that is, when it reaches 30 minutes, it is determined in step S119 whether or not the odor index N exceeds a predetermined value, for example, 0.3. , The odor index N is 0.3
If it exceeds, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when the odor is detected, the resistance value Z _n is not updated and the resistance value Z _n measured 30 minutes before is displayed on the LCD 6.

If the odor index N does not exceed a predetermined value, for example, 0.3 in step S119, that is, if no odor is detected, the measured resistance value Z _n of the measured resistance value Z _n is updated in step S123. The average value ΣZ _n / t is calculated, the value is replaced with the correction resistance value Z _nc in the environment, and the value is displayed in the display area 45b of the RAM 45.
To be stored. When calculating the average value, the measured resistance value Z
_{The n} may be stored in the work area 45a of the RAM 45 and summed at the time of update and divided by the number to calculate the average value. However, since the capacity of the RAM 45 is required for that purpose, storing only the total value causes Capacity is simplified.

When the process of step S123 is completed, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the display area 45b of the RAM 45 is displayed.
, The stored resistance value Z _n is stored in the LCD 6
To be displayed. If the auto-calibration setting function is in the OFF state by referring to the setting area 45c of the RAM 45 in step S115, the process immediately proceeds to step S118 and the contents of the display area 45b of the RAM 45 is displayed on the LCD 6.
To be displayed.

Next, in FIG. 12, in step S115, it is determined whether the auto-calibration setting function is in the ON state or the OFF state by referring to the setting area 45c of the RAM 45. If it is in the ON state, the automatic calibration setting function is executed in step S116. Increment the coefficient t associated with the calibration by one. Then, in step S124, the difference value ΔZ (absolute value) between the measured resistance value Z _n and the corrected resistance value Z _nc in the environment is calculated each time the odor index N is calculated,
In step S125, the difference value ΔZ and the predetermined value Δ
Compare with Z _P. This predetermined value ΔZ _P is the original measured resistance value Z
It is a value obtained by subtracting the correction resistance value Z _nc in the environment from the value Z _np closest to _n .

If ΔZ exceeds ΔZ _P in step S125, the process proceeds to step S117 as it is, and if ΔZ exceeds ΔZ _P , in step S126 Z _n is set as Z _np and ΔZ is set as ΔZ _P in the display area of the RAM 45. After storing, the process proceeds to step S117. Then, in step S117, the coefficient t is compared with the predetermined number T, and the coefficient t
Is not equal to the predetermined number T, that is, when 30 minutes have not elapsed, the RAM 45 is determined in step S118.
The content of the display area 45b, that is, the resistance value Z _np measured 30 minutes before is displayed on the LCD 6.

On the other hand, when the coefficient t becomes equal to the predetermined number T in step S117, that is, when it reaches 30 minutes, it is determined in step S119 whether the odor index N exceeds a predetermined value, for example, 0.3. , The odor index N is 0.3
If it exceeds, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the same operation as described above is performed. That is, when the odor is detected, the resistance value Z _n is not updated and the resistance value Z _np measured 30 minutes before is displayed on the LCD 6.

In step S119, if the odor index N does not exceed a predetermined value, for example, 0.3, that is, if odor is not detected, in step S127, Z _{np is set} to Z _{nc at the} update timing. In addition, ΔZ _P is replaced with the largest value (maximum value) in calculation, for example, 9.9, and that value is displayed in the display area 45 of the RAM 45.
Store in b. In this case as well, as in the case of taking the average value, each measured resistance value Z _n may be stored in the work area 45a of the RAM 45 and the respective values may be compared at the time of updating to obtain the latest value. Since the capacity of the RAM 45 is required, the capacity is simplified by comparing the difference values for each detection and storing only the closest value.

When the process of step S127 is completed, the coefficient t is set to 0 in step S121, the process proceeds to step S118, and the display area 45b of the RAM 45 is displayed.
, The stored resistance value Z _nc, etc. on the LCD
Display in 6. If the auto-calibration setting function is OFF in step S115 with reference to the setting area 45c of the RAM 45, immediately step S118 is performed.
Proceed to, and display the contents of the display area 45b of the RAM 45 on the LCD.
Display in 6. In the above embodiment, the case where the odor monitor is a portable type has been described. However, the odor monitor is not limited to this, and the odor monitor is provided in each room of the building to perform the same operation as in FIG. The odor index is calculated individually, the odor index of each room is individually collected, and the system can be similarly applied to the case of a stationary type having a receiving unit that performs the operation of the discrimination process (step S8) of FIG. , Produces the same effect.

Next, a method of correcting the voltage loss by the extension cord will be described with reference to FIGS. First, the case where the voltage drop based on the line length of the extension cord is measured and the voltage loss due to the extension cord is corrected will be described with reference to FIGS. 13 and 14. FIG. 13 is a monitor main body including an odor sensor 2 as a sensor unit for detecting odor, an MPU 4 as a signal processing unit for processing a signal from the sensor unit, an LCD 6 as a display unit for displaying the result, and the like. It is a block diagram which shows an example which has a structure which can be separated via an extension cord.

In the figure, MB is the monitor body,
This monitor main body MB includes all of the components other than the odor sensor 2 among the components shown in FIG.
Here, for convenience of explanation, only the MPU 4, the power supply circuit 11, the voltage regulator 12, and the variable voltage regulator 13 are shown. Further, EC is an extension cord, and this extension cord EC is an element 2a and a heater 2b for heating the element 2a.
The odor sensor 2 composed of and is electrically connected to the monitor body MB. Reference numeral 21 is a socket provided on the monitor body MB side. The odor sensor 2 is placed in this socket 21.
A plug (not shown), to which the extension cord EC from and the one end of a line LN described later are connected, is inserted. The temperature of the heater 2b changes in proportion to the amount of current supplied. The voltage drop in the extension cord EC due to the constant voltage supply lowers the amount of current supplied, resulting in a drop in temperature.

As the variable voltage regulator 13, a constant voltage circuit controllable by a signal from the MPU 4 is used here as an example. The voltage regulator 12 is connected to one end of the element 2a of the odor sensor 2 via the voltage dividing resistor 22 and the extension cord EC, and is also connected to the A / D via the voltage dividing resistor 22.
It is connected to the input end of the conversion unit 42, and the other end of the element 2a is grounded via the extension cord EC. Variable voltage regulator 13
Is the heater 2b of the odor sensor 2 via the extension cord EC.
Is connected to one end of the
It is connected to the input end of the D conversion unit 46, and the other end of the heater 2b is grounded via the extension cord EC.

Further, a fixed resistor 24 for measuring a voltage drop amount based on the line length of the extension cord EC is provided inside the odor sensor 2, and one end thereof is provided in the MPU 4 via one of the lines LN. In addition to being connected to the input terminal of the A / D converter 46A, it is also connected to the variable voltage regulator 13 via the voltage dividing resistor 25. The other end of the fixed resistor 24 is grounded via the other of the line LN. As the value of the fixed resistor 24, a value corresponding to a combined value of the resistance value of the extension cable EC and the resistance value of the line LN is used.

In FIG. 14, the fixed resistor 24 is connected to the odor sensor 2.
In the figure, the plug 2c of the odor sensor 2 has, for example, a plurality of pins P1 to P7, and as an example, between any two of the pins P1 to P3. The element 2a is connected, and the heater 2b is connected between the pins P5 and P6. Therefore, the fixed resistor 24 is connected between the remaining pins P4 and P7. In this method, the MPU 4 corresponds to the line length detection unit.

In such a configuration, the voltage value resistance-divided on the monitor body MB side, that is, the value of the voltage generated across the fixed resistor 24 is A / D converted by the A / D converter 46A and taken into the MPU 4. Since the resistance value and the supply voltage are known in the MPU 4, the resistance value of the extension cord EC can be calculated. The supply voltage is calculated in consideration of the calculated resistance value. That is, now, the resistance value of the heater 2b is Rh (Ω), the value of the voltage applied to the heater 2b is Vh (V), and the resistance value of the extension cable EC is Rd (Ω).
Then, the correction voltage Vd (V) can be calculated by the following equation.

Vd = (Rd / Rh) · Vh (4)

Considering this correction voltage Vd, the MPU 4
The supply voltage is determined and the supply voltage from the variable voltage regulator 13 is adjusted by port control. As a result, the voltage loss due to the extension cord EC is corrected, and a constant voltage can always be supplied to the heater 2b of the odor sensor 2.
The fixed resistor 2 provided in the odor sensor 2
Since the power supply to 4 is not always required, it is preferable to provide a switch means (not shown) for stopping the power supply after the adjustment of the variable voltage regulator 13. Further, the power supply to the heater 2b and the power supply to the fixed resistor 24 may be switched.

Further, in this method, it is necessary to calculate the supply voltage on the software of the MPU 4, but this is sufficient when the odor monitor is started up. Therefore, the supply voltage can be directly supplied at the end of the initialization routine. And the division voltage for recognizing the resistance value of the resistance-divided extension cable is A
/ D conversion and import. Then, calculate the supply voltage,
Make the setting output of the supply voltage. If this operation is always performed, this setting operation may be included in the normal routine after warm-up.

Next, with reference to FIG. 15 and FIG. 16, description will be made on the case of correcting the voltage loss in the extension cord depending on the shape of the plug, for example, the presence or absence of a plurality of specific pins.
Note that, in FIG. 15, parts corresponding to those in FIG. 13 are denoted by the same reference numerals, and detailed description thereof will be omitted. in this way,
Set the length of each pin of the plug so as to correspond to the length of the extension cord EC, and place the odor sensor 2 on the monitor body M.
When the switch is attached to the B side, the switches corresponding to the pins are arranged so as to be operated, and the line length detection unit by the switch group sets the supply voltage of the variable voltage regulator.

In FIG. 15, a line length detector 20 using a switch group is provided for the variable voltage regulator 13 in the monitor body MB, and the variable voltage regulator 13 is controlled based on the output thereof. Therefore, in this case, the control of the variable voltage regulator 13 by the MPU 4 is unnecessary, and the fixed resistor 24 is also unnecessary. FIG. 16 shows the line length detection unit 20.
Shows the relative relationship between an example of the switch group and the pin of the plug corresponding to this switch group. In the figure, reference numeral 26 is a switch group including a plurality of, for example, two push button switches. The on / off button of each push button switch is a socket 21 on the monitor main body MB side into which each pin of the plug 2c of the odor sensor 2 is inserted. It is designed to correspond to the hole. A plurality of lengths of the extension cord EC are prepared in advance, and the length of each pin of the plug 2c corresponding to the length of the extension cord EC is shown in, for example, (a) to (d) of FIG. Is decided.

That is, in FIG. 16A, when the pins P7 and P4 are both long and substantially both pins exist, in FIG. 16B, the pin P7 is long and the pin P4 is short, and substantially. 16C shows the case where only the pin P7 on the left side of the drawing exists, FIG. 16C shows that when the pin P7 is short and the pin P4 is long and substantially only the pin P4 on the right side of the drawing exists. Shows the case where both the pin P7 and the pin P4 are short and both pins are substantially absent, and a plurality of types of extension cords EC having different lengths are present corresponding to each of these cases. 16B to 16D, the socket 21 and the switch group 26 are omitted. Further, although not shown, the socket 21 of the extension cord EC
The pin of the plug on the side also has the same shape as the pin of the plug 2c of the odor sensor 2, and here, for convenience, the plug 2c is used.
The case where is inserted into the socket 21 will be described.

In this structure, when the odor sensor 2 is mounted on the monitor main body MB, in the case of FIG. 16A, the push button switches of the switch group 26 are both turned on by the pins P7 and P4. In case of (b), pin P
7 only turns on, in the case of FIG. 16 (c), only the push button switch corresponding to pin P4 turns on, and in the case of FIG. 16 (d), pins P7 and P4.
Both push button switches corresponding to are turned off. Since the state of each push button is set so as to correspond to a plurality of different types of extension cords, the voltage supplied to the heater 2b of the odor sensor 2 is set in the variable voltage regulator 13 according to this state. Set. As a result, the voltage loss due to the extension cord EC is corrected, and a constant voltage can always be supplied to the heater 2b of the odor sensor 2.

The state of each push button of the switch group 26 is stored in the memory of the MPU 4 in advance, and the odor sensor 2
The plug 2c may be grasped when it is inserted into the socket 21 on the monitor body MB side, and the MPU 4 may control the variable voltage regulator 13. Further, here, the case where the shape of the plug is identified by using the two pins of the plug 2c of the odor sensor 2 and the line length of the extension cord is detected based on the identification result has been described, but the present invention is not limited to this. Alternatively, for example, all of the plurality of pins of the plug 2c may be used, or mold pins provided separately from the plug may be used.

Next, referring to FIGS. 17 and 18, a case will be described in which the voltage loss of the extension cord is corrected based on the shape of the plug, for example, the length of a specific pin. In FIG. 17, parts corresponding to those in FIG. 15 are designated by the same reference numerals, and detailed description thereof will be omitted. In this method, the length of a specific pin of the plug is set so as to correspond to the length of the extension cord EC, and when the odor sensor 2 is mounted on the monitor body MB side, the line length is set by the specific pin. The variable resistor as the detection unit 20 is arranged so as to be operated, and the line length detection unit by the variable resistor sets the supply voltage of the variable voltage regulator.

In FIG. 17, a line length detector 20 using a variable resistor 27 is provided for the variable voltage regulator 13 in the monitor body MB, and the variable voltage regulator 13 is controlled based on the output thereof. To do. The variable voltage regulator 13 in this case also has the same function as that of FIG.
FIG. 18 shows a variable resistor 27 as the line length detection unit 20,
This shows the relative relationship with the corresponding pins of the plug. In the figure, the specific pin of the plug 2c of the odor sensor 2, for example, the pin P4, has its length adjusted corresponding to the specific one of the plurality of types of extension cords EC having different lengths. Then, of the holes of the socket 21 into which the pins of the plug 2c are inserted, the variable resistor 27 is monitored so that the sliding terminals of the variable resistor 27 are below the holes into which the specific pin P4 is inserted. It is positioned on the body MB side. The sliding terminal of the variable resistor 27 is constantly urged upward by an elastic body such as a spring (not shown). In this case as well, although not shown, the pin of the plug of the extension cord EC on the socket 21 side also has the same shape as the pin of the plug 2c of the odor sensor 2, and here the plug 2c is inserted into the socket 21 for convenience. The case will be described.

In such a structure, when the odor sensor 2 is attached to the monitor body MB, the plug 2c of the odor sensor 2 is inserted into the socket 21 and the pin P of the plug 2c is inserted.
By the length of 4, the sliding terminal of the variable resistor 26 moves downward and its resistance value is set. Further, since the variable resistor 26 is electrically connected to the variable voltage regulator 13, the variable voltage regulator 13 uses the resistance value of the variable resistor 26 at this time as a heater for the odor sensor 2. Set the voltage supplied to 2b. This allows extension cord E
The voltage loss due to C is corrected, and a constant voltage can always be supplied to the heater 2b of the odor sensor 2.

Also in this case, a plurality of types of extension cords having different lengths are prepared in advance, and the resistance value of the variable resistor 26 corresponding to the length of each extension cord is stored and stored in the memory of the MPU 4. The resistance value of the variable resistor 26 may be taken into the MPU 4 when the plug 2c of the odor sensor 2 is inserted into the socket 21 on the monitor body MB side, and the MPU 4 may control the variable voltage regulator 13.

In this way, even when the sensor unit including the odor sensor and the monitor body are separable via the extension cord, the voltage drop amount based on the line length of the extension cord is automatically corrected. A constant heater voltage can always be secured, and stable operation can be secured.

[0108]

As described above, according to the present invention, the odor sensor for detecting the atmosphere in the environment, the signal processor and the odor sensor which are separated from the odor sensor and process the detection output of the odor sensor are provided. A monitor body including a power supply means for supplying a voltage, an extension cord electrically connecting the odor sensor and the monitor body, a detection means for detecting the line length of the extension cord, and a voltage drop amount based on the line length of the extension cord. Since there is provided a correction means for correcting the above, there is an effect that the voltage loss due to the extension cord is automatically corrected, stable operation can always be ensured, and reliability can be improved.

Further, as the detecting means, a fixed resistor corresponding to at least the resistance value of the extension cord is provided in the odor sensor, and the correcting means determines the voltage supplied to the odor sensor based on the voltage drop in the fixed resistor. I will adjust
The extension cord can be identified by simply installing a fixed resistor that has a resistance value equivalent to the resistance value of the extension cord in the odor sensor, and the voltage loss due to the extension cord is automatically corrected to ensure stable operation. There is an effect that the operation can be secured and the reliability can be improved with a simple configuration.

Further, when the odor sensor and the monitor main body are attached, the detection means corresponds to the shape of the odor sensor plug which is preset corresponding to the line lengths of a plurality of types of extension cords having different lengths. The extension cord is identified, and the correction means adjusts the voltage supplied to the odor sensor based on the identification result, so that the extension cord can be easily and reliably identified only by checking the shape of the plug. There is an effect that the voltage loss due to is automatically corrected, stable operation can always be secured, and the reliability can be improved with a simple configuration.

Further, the detecting means determines, when the odor sensor and the monitor body are attached, whether or not any of a plurality of specific pins of the plug of the odor sensor contacts a switch group provided facing the pin. Since the corresponding extension cord is identified, you can easily and reliably identify the extension cord just by checking the presence or absence of multiple specific pins on the plug, and the voltage loss due to the extension cord is automatically corrected to ensure stable operation. It is possible to secure the above-mentioned operation and improve reliability with a simple configuration.

Further, the detecting means is such that when the odor sensor and the monitor main body are attached, the specific pin of the odor sensor plug is
Since the corresponding extension cord is identified based on the resistance value when the sliding terminal of the variable resistor provided facing this pin is moved, it is easy to change the length of the specific pin of the plug. In addition, the extension cord can be identified, the voltage loss caused by the extension cord can be automatically corrected, and stable operation can always be ensured, and the reliability can be improved with a simple configuration.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an odor monitor according to the present invention.

FIG. 2 is a block diagram showing a main part of an embodiment of an odor monitor according to the present invention.

FIG. 3 is a flowchart for explaining the overall operation of FIG.

FIG. 4 is a flowchart for providing a detailed description of an initial setting operation in FIG.

5 is a flowchart for providing a detailed description of an operation of a setting process in FIG.

FIG. 6 is a flowchart for providing a detailed description of an operation of a setting process in FIG.

7 is a flowchart for providing a detailed description of an operation of a setting process in FIG.

8 is a flowchart for providing a detailed description of a data reading operation in FIG.

9 is a flowchart for providing a detailed description of the operation of odor index conversion in FIG.

10 is a flowchart for providing a detailed description of the operation of the determination process in FIG.

11 is a flowchart for providing a detailed description of an operation of another example of the automatic calibration in FIG.

FIG. 12 is a flowchart for providing a detailed description of the operation of still another example of the automatic calibration in FIG.

FIG. 13 is a configuration diagram showing an example of correcting a voltage loss component due to an extension cord connecting the odor sensor having a separated structure and a monitor body.

FIG. 14 is a layout view showing a main part in FIG.

FIG. 15 is a configuration diagram showing another example of correcting a voltage loss due to an extension cord connecting the odor sensor having a separate structure and a monitor main body.

16 is a layout view showing a main part in FIG.

FIG. 17 is a configuration diagram showing another example of correcting a voltage loss component due to an extension cord connecting the odor sensor having a separated structure and a monitor main body.

FIG. 18 is a layout view showing a main part in FIG.

[Explanation of symbols]

 1 odor monitor 2 odor sensor 2a element 2b heater 4 microprocessor unit (MPU) 41 arithmetic unit 7 EEPROM 11 power supply circuit 12 voltage regulator 13 variable voltage regulator 20 line length detector 24 fixed resistor 26 pushbutton switch 27 variable Resistor MB Monitor body EC extension cord

Claims (5)

[Claims] 1. A monitor including an odor sensor for detecting an atmosphere in the environment, a signal processing section which is separated from the odor sensor and which processes a detection output of the odor sensor, and a power supply means for supplying a voltage to the odor sensor. A main body, an extension cord electrically connecting the odor sensor and the monitor main body, detection means for detecting the line length of the extension cord, and correction means for correcting a voltage drop amount based on the line length of the extension cord. An odor monitor characterized by having. 2. A fixed resistor having a resistance value corresponding to at least the resistance value of the extension cord is provided in the odor sensor as the detection means, and the correction means is based on a voltage drop in the fixed resistor. The odor monitor according to claim 1, wherein a voltage supplied to the odor sensor is adjusted. 3. The detecting means is based on the shape of the plug of the odor sensor which is preset in correspondence with the line lengths of a plurality of types of extension cords having different lengths when the odor sensor and the monitor body are mounted. 2. The odor monitor according to claim 1, wherein the corresponding extension code is identified, and the correction means adjusts the voltage supplied to the odor sensor based on the identification result. 4. The detecting means, when the odor sensor and the monitor main body are mounted, any one of a plurality of specific pins of a plug of the odor sensor contacts a switch group provided facing the pin. 4. The odor monitor according to claim 3, wherein the corresponding extension cord is identified depending on whether or not it is. 5. The detection means, when the odor sensor and the monitor main body are attached, a specific pin of a plug of the odor sensor moves a sliding terminal of a variable resistor provided facing the pin. The odor monitor according to claim 3, wherein the corresponding extension cord is identified based on the resistance value when the extension cord is caused to move.