JP2964342B2 - Automatic electrode cleaning / calibration equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cleaning / calibration apparatus for electrodes, and more particularly to a method for chemically removing scale attached to an electrode such as a pH meter and calibrating an instrument with a calibration solution. And an automatic electrode cleaning / calibration method for automatically performing the above steps.

2. Description of the Related Art For example, cleaning with a chemical solution in a glass electrode type pH meter, which is widely used, has been practically used as a method for chemically decomposing electrode stains.

Some calibration devices with chemical cleaning have been proposed in which instrument calibration with a calibration liquid is added to this chemical cleaning device.

In these conventional devices, the electrode section needs to be isolated from the liquid to be measured during cleaning and calibration, so that the electrode section is generally lifted upward from the liquid to be measured. This is to lift the electrode above the water surface of the measuring tank,
When the water level is deep and it is intended to measure the pH value at the lower part of the measuring tank, a large lifting is required, and the lifting length needs to be adjusted by the length of the holder.

In addition, a method of discharging used washing water, a chemical solution, and a calibration solution into a measurement tank is generally performed because the operation and the mechanism can be easily configured.

Furthermore, the transfer from the calibration liquid tank to the electrode unit is performed by a pump. This has the advantage of providing a certain degree of freedom in the installation location of the electrode holder, but can be a drawback when considering the life of the pump and the like.

Problems to be Solved by the Invention However, the above-described prior art has the following disadvantages.

In the conventional calibration device with a chemical solution, all the processing operations are performed manually, so that not only manual operations are required but also operation errors are required and a great amount of time is required.

In addition, in the conventional method, the electrode holder is required to be lifted above the surface of the liquid to be measured in some cases, so that the electrode holder needs to be greatly pulled up.

Furthermore, discharging the washing water, chemical solution, and calibration solution used for use to the measurement target tank is that when the measurement target tank is small and the amount of the measurement target liquid to be handled is small, the measurement target liquid contains the chemical solution or the like. There is a problem that an undesirable phenomenon is caused as a result of the mixing.

Conventionally, when the sequence is in the running state, cleaning and calibration measurement are repeated at a predetermined cycle, and it is possible to perform cleaning → calibration → measurement at any time in the measurement state by an external switch or the like. However, washing → measurement, calibration → measurement, and washing → calibration → measurement are arbitrarily selected, and furthermore, it is impossible to stop (continue the state) during washing and calibration as well as during measurement.

The present invention has been made in view of the above-described conventional circumstances, and accordingly, an object of the present invention is to provide a novel electrode automatic cleaning / calibration apparatus capable of solving the above-described drawbacks inherent in the conventional technology. Is to do.

Means for Solving the Problems To achieve the above object, an automatic electrode cleaning / calibration apparatus according to the present invention includes a cleaning / calibration unit provided in a liquid to be measured and provided with a measurement electrode, a chemical solution tank, A tank unit having four tanks, a first standard liquid tank, a second standard liquid tank, and a washing water tank, and a liquid electromagnetic valve; an operation panel, a sequence unit, and an air electromagnetic valve; A control unit that controls the cleaning / calibration unit and the liquid / air solenoid valve in accordance with a sequence step stored in a ROM provided in the operation panel and programmed in advance to perform cleaning of the measurement electrode and calibration of a standard solution by controlling the electromagnetic valve for air; and It is comprised including.

Next, a preferred embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the cleaning calibration unit shown in FIG. 1 in a measurement state, and FIG. 3 is a cleaning calibrator main body of the cleaning calibration unit. FIG. 4 is an enlarged partial cross-sectional view showing a state at the time of cleaning / calibration of a part, FIG. 4 is a block diagram showing an embodiment of the present invention,
FIG. 5 is a front view showing an operation panel surface panel of the control unit, FIG. 6 is a block diagram showing an embodiment of a sequence control unit provided in a microcomputer built-in indicator in the operation panel of the control unit, FIG. 7 is a schematic flowchart showing one embodiment of the automatic cleaning / configuration process according to the present invention.

1 to 7, reference numeral 1 denotes a control unit. The control unit 1 has an operation panel 4, a sequence unit 5, and an electrode valve 6 for air.
The cleaning / calibration unit 2 and the electromagnetic air for air are stored in a ROM 443 (FIG. 6) provided in a microcomputer built-in indicator (for example, a pH meter, an ORP meter) 44 provided therein. The valve 6 and the liquid solenoid valves 20 to 24 are controlled to perform cleaning of the measurement electrode 100 and calibration of the standard solution. The control unit 1 can also externally forcibly perform a calibration start for forcing a sequence stop, and a function of displaying a status state together with a measured value display on a lamp display and a display of an indicator and transmitting information to the outside. It has the function to do.

The operation panel 4 has an operation switch 41, a sequence status display unit 42 (DISP447 in FIG. 6), a remote / local switch 43, a microcomputer built-in indicator 44, and a sequence status display lamp 45.

The sequence unit 5 is a relay circuit board 5
1. It has a timing circuit board 52, an operation remote input unit 53, and a status contact output unit 54.

The indicator 44 with a built-in microcomputer controls the sequence steps, determines an electromagnetic valve to be operated for each step, and sends an operation signal to the relay circuit board 51. The relay circuit board 51 operates only the relay (RL) from which this signal has been sent. Relay contacts and solenoid valves correspond individually (eg, RL ₁ → SV ₁ , RL ₂ → SV ₂ etc.).

The timing circuit board 52 is provided with five external operation inputs. This input enters the microcomputer built-in indicator 44, and an operation corresponding to each input is performed. In other words, five sets of signal lines to the indicator are required for five inputs, and generally, I / O ports are required. In this apparatus, only one set of signal lines, that is, one set of I / O ports is used, and there is an advantage that not only I / O ports can be saved but also peripheral electric devices can be reduced.

The operation panel switch (S
When there are five types of W), the input unit is configured as shown in FIG. In this case, a pulse wave having a pulse width corresponding to the type of switch is output using the sequence unit 5. The pulse enters the meter as input. It is a feature of the present invention that the operation unit is configured as an input unit shown in the drawing.

With the connection configuration shown in FIG. 14, I / O of indicator such as pH meter
The feature is that the number of O ports used can be saved, the number of terminal boards in the operation panel can be saved, the parts of the photocoupler used for the I / O ports can be saved, and the size of the mounting printed board can be saved. .

The relay circuit board 51 and the timing circuit board 52 are configured as shown in FIG. 15, and the timing circuit in the sequence unit 5 converting five types of operation units as one input using FIGS. board
A description will be given as to how the pulse wave is output for 52.

When the switch SW2 is turned on, the output point a2 of the NOR gate NOR2 becomes “H”.
igh ”level, and the Q output of flip-flop FF2 also becomes“ H ”.
igh "level. This output becomes the input of the OR gate OR and the input of the pulse generator 17. The frequency from the pulse generator 17
A pulse of f2 is generated, and a voltage is applied from the output of the pulse generator 17 to the R (RESET) terminals of all flip-flops FF. The timing chart at this time is shown in FIG.

By connecting a cable to the remote input unit 53 for operation, a make contact signal is instantly given to this input unit 53 from an instrument room, etc., distant from the site, so that start, washing start, calibration start, washing / calibration start , Stop, etc. can be operated remotely.

Status information is extracted from the status contact output unit 54 by a relay contact output, and the information can be transmitted to an instrument room or the like remote from the site using the contact output.

The air solenoid valve 6 includes solenoid valves 25, 26, 27, and 28 and has a pressure switch 61.

The cleaning / calibration unit 2 is disposed in the liquid to be measured, is fixed to the main body, and the lower portion is disposed in the liquid to be measured.
A cleaning calibrator 9 having a pipe 91 provided with a packing 92 at a lower end thereof;
And an electrode holder 10 having an electrode cover 101 that accommodates the measurement electrode 100 at the lower end thereof and moves up and down along the longitudinal direction of the pipe 91 so as to have Cleaning calibration unit 2
At the time of measurement, the electrode cover 101 is placed at the lowest position so that the measurement electrode 100 comes into contact with the liquid to be measured. During cleaning and calibration, the electrode cover 101 is placed at the top position and the large-diameter portion 101a at the tip of the electrode cover 101 has a pipe. It contacts the packing 92 provided at the lower end of 91 and acts so that the electrode cleaning / calibration space 99 is sealed. Air is supplied through the resistance tube R1 so that the liquid to be measured is not introduced into the electrode cleaning / calibration space 99.

The tank unit 3 includes a chemical solution tank 29, a standard solution (eg, pH 7) tank 30, and a standard solution tank (eg, pH 4 or pH 4).
9) It has a tank 31 and a washing water (tap water) tank 32. Tanks 30, 31, and 32 have liquid level switches 11, 1 respectively.
2, 13 are provided, and liquid solenoid valves 20, 21, 22, 23, 24 are provided corresponding to the tanks 29, 30, 31, 32, respectively.

As shown in the schematic flow of FIG. 7, in the present invention, each process is continuously executed according to the sequence of measurement → sequence start → cleaning, calibration → standby → measurement.

FIG. 8 is a flowchart showing the sequence steps of the present invention in detail, and FIGS. 9 to 11 are schematic layout diagrams of all the parts for explaining the processing steps of the present invention. FIG. 10 is a layout diagram in the case where the liquid is injected by a difference in the mounting position between the tanks 29 to 32 and the electromagnetic cleaning / calibration space 99, that is, the head pressure difference, and the used chemical liquid is collected in the original tank 29. The figure is a layout diagram in which the injection of the liquid is performed by the head difference and the used chemical liquid is collected in another tank 33,
FIG. 11 is a layout diagram in which the liquid is injected by the pump 34 and the used chemical solution is collected in the original tank 29 or another tank 33. FIG. This is a process for removing the water remaining in the middle of the piping and preventing the standard solution from being diluted.
2 is pH4, indicating that a pH9 standard may be used depending on the process.

Next, the operation of the present invention will be described in detail with reference to FIGS.

. Measurement state Air is supplied through the resistance tube R1 so that the liquid to be measured does not enter the cleaning calibrator 9.

. Cleaning start The solenoid valves 25 and 26 are opened, the cylinder 80 rises while supplying a large amount of air, and the cleaning / calibrator 9 rises. Lower packing 92 of cleaning / calibrator 9 and electrode cover 10 of electrode holder 10
The large-diameter portion 101a is closely attached to form a cleaning / calibration space 99 below the cleaning / calibrator 9.

. Cleaning solution injection The electromagnetic valve 27 is opened, and the cleaning calibration space 99 is opened to the atmosphere. Subsequently, the electromagnetic valve 20 is opened for a set time, and the cleaning liquid is injected into the space 99 using the head difference.

. The cleaning electromagnetic valve 28 is opened for a set time, and air is introduced through the resistance tube R2. Due to the introduced air, the space 99
Bubbling and cleaning of the chemical solution injected into the.

. Collection The solenoid valves 26, 20, and 28 are opened again, and the tank 29
The chemical is pumped and collected.

. Cleaning water injection The solenoid valve 27 opens, and the space 99 is opened to the atmosphere.
Is opened, and tap water is injected into the space 99.

. Cleaning As in the case of cleaning with a chemical, the electromagnetic valve 28 is opened and bubbling is performed to wash the chemical.

. Discharge Solenoid valves 26, 28 and 24 are opened and discharged to the outside of the cleaning / calibrator 9 by the pressure of air. Steps (1) to (4) are performed a preset number of times.

. Standby (1) Open the solenoid valves 27 and 21 and inject the standard solution (pH 7) from the tank 30 into the space 99. Next, the solenoid valve 28 is opened, and air is sent through the resistance pipe R2 to blow into the standard solution. Co-wash with standard solution to reduce the effects of cleaning solution. After the end, the solenoid valve 24 is opened to discharge.

. Standard solution calibration (1) Inject a standard solution of pH 7 and blow air for a short time to stir and homogenize the solution in the same manner as above, and send a signal to the indicator (pH meter). The pH meter captures this signal when the input signal is stable.

. Discharge The solenoid valves 26, 28 and 24 are opened in response to the signal of the completion of the calibration, and the pH7 standard solution is discharged out of the washing / calibrator 9.

. Washing Open solenoid valves 27 and 22 and inject washing water. Next, solenoid valve 2
Open 8 and blow air to wash out the standard solution adhering inside the electrode cleaning calibrator.

. Discharge When cleaning is completed, the solenoid valves 26 and 24 are opened, air is sent into the cleaning calibrator, and the air is discharged out of the cleaning calibrator by pressure.

. Standby (2) Open the solenoid valve 27 and open the inside of the cleaning calibrator to the atmosphere. Next, the solenoid valve 21 is opened, and pH 4 or pH 9 is supplied from the tank 31.
Is injected into the cleaning calibrator 9. Next, the electromagnetic valve 28 is opened, and the washing liquid is washed together with the standard liquid. Solenoid valve 26, 28, 24
Is opened to send air into the cleaning calibrator and discharge it out of the cleaning calibrator by air pressure.

. Standard solution calibration (2) As in the case of standby (2) above, a standard solution of pH4 or pH9 is injected, air is briefly blown, the solution is stirred and homogenized, and a signal is sent to the pH meter. When the input signal is stabilized, the pH meter takes in this signal and calculates STD.SLOPE using the signal of the standard calibration (1) and the signal of the standard solution calibration (2).

. Discharge Open the solenoid valves 26, 28 and 24 to send air into the cleaning calibrator and discharge it out of the cleaning calibrator by air pressure.

. The electromagnetic valve 27 is opened to open the inside of the cleaning calibrator to the atmosphere, and the electromagnetic valve 23 is opened to inject cleaning water from the tank 32. solenoid valve
Open 28 to clean and discharge the inside of the electrode cleaning calibrator.

. The solenoid valve 25 is switched to lower the cylinder 80, and the electrode 100 is lowered below the cleaning calibrator 10. Air is flowed through the resistance tube R1 to exhaust the liquid to be measured so as not to enter the cleaning calibrator. Measurement does not start until a certain time has elapsed.

The above description has been made with reference to FIG. 9. However, the case of FIG. 10 is the same as that of FIG. 9 except that the used chemical is collected in another tank 33. In addition, in the case of FIG. 11, all the liquid injection is performed by using the pump 34 and the used chemical liquid is collected in the original tank 29 or another tank 33, and the other is the same as in FIG. This is the same as the case described above.

In the present invention, among the processing steps in the sequence shown in FIG. 8, the currently executed processing step and the processing step to be executed next are displayed on the sequence state display section 42 on the panel surface. FIG. 12 is a flowchart showing an example of the sequence state display flow.

FIG. 13 is a flowchart showing an example of a forced start interrupt flow.

In the present invention, it is possible to operate the remote / local changeover switch 43 shown in FIG. At that time, KEY446 shown in Fig. 6
To set the time. KEY446 is used to set the time for cleaning and calibrating the sequence, but is also used for this interrupt. The time set by KEY446 is stored in RAM442.

In the present invention, the self-diagnosis of the measurement electrode 100 can be performed.

That is, by performing the standard solution calibration, the characteristics (deterioration state) of the electrode used can be known. The pH values of the two aqueous solutions X and S at the same temperature are expressed as pH (X) and pH (S), respectively.
Expressed in _{E X -E S = α G {} pH (X) -pH (S)} ...... (1) E X: the electromotive force E _S battery that combines the reference electrode and the glass electrode in an aqueous solution X : Electromotive force of a battery in which a glass electrode and a reference electrode are combined in an aqueous solution S α _G : Proportional coefficient (electromotive force per pH) alpha _G is the electromotive force of a glass electrode per 1pH at the measurement temperature, E _X, E _S, the value of pH (S) is determined is for alpha _G to be known at the time of standard solution calibration. The value of α _G is a function of temperature. 1p when hydrogen electrode is used instead of glass electrode
(The alpha _H) power per H comparing the values of alpha _G as a reference.

K = 100 × α _G / α _H (2) K: SLOPE of the electrode When K ≧ 90%, the glass electrode sensitivity is in a good state, and K <90%.
At this time, the ALM / FAIL lamp flashes to call attention to check the electrodes.

In addition to this K, what can be confirmed when calibrating the standard solution is pH7
And important data for checking the pH electrode characteristics together with K. The initial electromotive force at pH 7 is about ± 10 mV, but it increases when used and deteriorates. This value is converted into a pH value at 25 ° C. and displayed. PH (ST
D). The electrode having a pH (STD) value of −1pH ≦ pH (STD) ≦ 1pH is regarded as a normal electrode.
As in the case of, a warning is issued by blinking the ALM / FAIL lamp. In practice, pH (STD) can be used up to ± 1.5 pH and K can be used up to 85%. That is, AL
Since the M / FAIL lamp notifies the user of a warning and warning of electrode deterioration before the electrode becomes completely defective, it is possible to smoothly handle electrode replacement and the like. Since this value is stored until the next calibration, if the calibration is performed after reading this value, the electrode deterioration tendency can be determined.

FIG. 17 is a diagram in which the above-mentioned operations of the present invention are put together into a time chart.

Effects of the Invention The present invention is configured and operates as described above, and according to the present invention, the following effects can be obtained.

. In the present invention, the cleaning, calibration, standby, and measurement processing steps are automatically performed according to a predetermined sequence, so that not only short-time processing is possible, but also labor can be saved, and It is possible to avoid human operation errors.

. In the present invention, the electrode cleaning device is closed from the liquid to be measured by the electrode holder with a slight upward movement.
A space for calibration is formed, and in this space, cleaning and calibration of the electrode are performed, so the drive means for moving the electrode holder up and down can be formed extremely small, and the cleaning and calibration of the electrode is optimized. It becomes possible to control.

. In the present invention, since the process currently being processed and the process to be executed next are simultaneously displayed on the outside, extremely effective information can be given to the monitor.

. In the present invention, the supply of the chemical solution, the standard solution, and the tap water to the electrode cleaning / calibration space is performed by the difference between the mounting positions of each tank and the space, that is, the head pressure difference. It is not necessary to use it, so that the number of parts is reduced and the failure rate is reduced.

. Also, by operating the remote / local changeover switch, from the outside (for example, a point separated from the apparatus), the sequence currently being processed can be started as needed, washing start, calibration start, washing / calibration start / stop, etc. Can be easily executed.

. Further, according to the present invention, self-diagnosis of the measurement electrode can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is an enlarged sectional view of the cleaning / calibration unit shown in FIG. 1 in a measurement state, and FIG. FIG. 4 is an enlarged partial sectional view showing the state of the calibrator body at the time of cleaning / calibration, FIG. 4 is a block diagram showing an embodiment of the present invention, FIG. 5 is a front view showing a control panel surface panel of the control unit, FIG. FIG. 6 is a block diagram showing an embodiment of a sequence control section provided in a microcomputer built-in indicator in the operation panel of the control unit. FIG. 7 is a flow chart of an automatic cleaning / calibration process according to the present invention. FIG. 8 is a schematic flow chart showing an embodiment, FIG. 8 is a flow chart showing the sequence steps of the present invention in detail, and FIGS. 9 to 11 are schematic layout diagrams of the whole parts for explaining the processing steps of the present invention. Figure 9 shows the liquid ( Liquid, standard solution, tap water) is injected by the head differential pressure and the used chemical solution is collected in the original tank. FIG. 10 is a diagram showing the injection of the liquid by the head differential pressure and the use after the use. Fig. 11 is a layout diagram in the case of collecting a chemical solution in another tank, Fig. 11 is a layout diagram in which a liquid is injected by a pump and the used chemical solution is collected in the original tank or another tank, and Fig. 12 is a sequence. 13 is a flowchart showing one embodiment of a status display flow, FIG. 13 is a flowchart showing one embodiment of a forced start interrupt flow, and FIG. 14 is a block diagram of one embodiment showing a method of connecting sequence units according to the present invention. FIG. 15 is a block diagram showing one embodiment of the timing circuit board according to the present invention, FIG. 16 is a timing chart showing the operation of the circuit shown in FIG. 15, and FIG. 17 is the overall operation of the present invention. Dress up It is a timing chart shown below. 1 ... control unit, 2 ... cleaning / calibration unit, 3 ...
… Tank unit, 4… operation panel, 5… sequence unit, 6 (25 to 28)… solenoid valve for air, 9… cleaning
Calibrator, 10 ... electrode holder, 11-13 ... level switch, 17 ... pulse generator, 20-24 ... solenoid valve for liquid, 29 ...
… Chemical liquid tank, 30, 31 …… Standard liquid tank, 32 …… Washing water tank, 33 …… Chemical liquid recovery tank, 34 …… Pump, 38
…… Solenoid valve, 41 …… Operation switch, 42 …… Sequence status display section, 43 …… Remote / local switch,
44 …… Indicator with built-in microcomputer, 45 …… Sequence status display lamp, 51 …… Relay circuit board,
52: Timing circuit board, 53: Remote input unit for operation, 54: Status contact output unit, 61: Pressure switch, 80: Cylinder, 82, 92: Packing, 91:
... pipe, 93 ... holding plate, 99 ... space for electrode cleaning / calibration, 100 ... measuring electrode, 101 ... electrode cover

Continuation of front page (72) Inventor Shuji Ota 3-20-8 Narita Nishi, Suginami-ku, Tokyo Okura Electric Co., Ltd. (72) Inventor Isamu 3-20-8 Narita Nishi, Suginami-ku, Tokyo Okura Electric Co., Ltd. (72) Inventor Minoru Kimura 3-20-8, Narita Nishi, Suginami-ku, Tokyo Okura Electric Co., Ltd. (56) References Jikai Sho 61-161657 (JP, U) (58) Fields surveyed (Int.Cl . ⁶ , DB name) G01N 27/38

Claims (6)

(57) [Claims] 1. A cleaning / calibration unit provided in a liquid to be measured and provided with a measurement electrode, and four chemical liquid tanks, a first standard liquid tank, a second standard liquid tank, and a cleaning water tank. A tank unit having a tank and a liquid solenoid valve, an operation panel, a sequence unit, and an air solenoid valve, and the cleaning calibration unit and the liquid and air solenoid valves are controlled in accordance with a previously programmed sequence process. A control unit for cleaning the measurement electrode and calibrating the standard solution.The cleaning / calibration unit includes a pipe fixed to the main body, arranged downward in the liquid to be measured, and provided with packing at the lower end. A cleaning calibrator having an electrode cover that moves up and down along the longitudinal direction of the pipe so as to have a space for electrode cleaning / calibration between the pipe and the measurement electrode at the lower end. The electrode cover is disposed at the lowest position during measurement and the electrode contacts the liquid to be measured, and the electrode cover is disposed at the highest position during cleaning and calibration, and the tip of the electrode cover is provided. The large-diameter portion having a tapered upper portion provided in the portion contacts the packing provided at the lower end of the pipe to seal the electrode cleaning / calibration space portion, and further covers the electrode cleaning / calibration space portion. Means for constantly supplying air so that the measurement liquid is not introduced, and the sequence step is stored in a ROM provided in a microcomputer built-in indicator provided in an operation panel of the control unit. An automatic electrode cleaning / calibration apparatus characterized in that: 2. The circuit unit of the control unit, wherein the sequence unit is activated by operation of a plurality of operation switches disposed on the operation panel and has a plurality of relay contacts corresponding to the respective switches; A plurality of NOR gates provided corresponding to the respective relay contacts, and a plurality of NOR gates each receiving an output of each relay contact, a plurality of flip-flops receiving the output of each NOR gate, and an output of each flip-flop as an input A pulse signal having a different pulse width is generated depending on the type of the operation switch, and a reset signal for inhibiting all other flip-flops when any one of the flip-flops is activated is activated. Further comprising: a timing circuit board having a pulse generator for generating the same. Electrode automatic cleaning and calibration apparatus according to claim (1) to. 3. An operation remote input unit is provided in the sequence unit, and an external interrupt signal can be input to the operation remote input unit or by operating an operation switch in the operation panel. The electrode automatic cleaning / calibration apparatus according to claim (1). 4. The apparatus for automatically cleaning and calibrating an electrode according to claim 1, further comprising display means for displaying a sequence state on said operation panel. 5. The control panel according to claim 1, further comprising a key for setting time required for cleaning, calibration, standby, and measurement, and storage means for storing the time set by the key. The electrode cleaning / calibration apparatus according to (1) or (4). 6. The automatic electrode cleaning / calibration apparatus according to claim 1, wherein each tank provided in the tank unit is arranged above the electrode cleaning / calibration space.