JPH02281120A - Pressure-gage calibrating apparatus - Google Patents

Abstract

PURPOSE:To make it possible to perform calibration at multiple points in a short time highly accurately by obtaining input/output characteristic curves based on mea sured pressure signals and calibrating pressures, comparing the input/output characteris tic curves with predetermined characteristic curves in specifications, and judging the accuracy of a pressure measuring means. CONSTITUTION:When a pressure measuring means 11 which measures the pressure in a plant, pressures corresponding to a plurality of calibrating pressures are sequential ly applied on the means 11 from a pressure generating means 12. The pressures which are applied to the means 11 from the means 12 at this time are measured with a precise pressure measuring means 13. The pressures generated in the means 12 are controlled so that the pressure which is measured with the means 13 becomes the predetermined calibrating pressure. A measured pressure signal which is measured with the means 11 for every calibrating pressure is received and stored in a control/ operating means 14. The input/output characteristic curves of the means 11 are obtained based on said measured pressure signal and the calibrating pressure. The accuracy of the means 11 can be judged based on the input/output characteristic curves and the characteristic curves in specifications which are provided beforehand for the means 11.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a pressure gauge calibration device that automatically calibrates a large number of pressure gauges installed in nuclear couplants and other various plants, and particularly relates to a pressure gauge calibration device that automatically calibrates a large number of pressure gauges installed in nuclear couplants and other various plants. This invention relates to a pressure gauge calibration device that saves labor.

(Prior art) In this type of industrial plant, pressure switches are installed at various locations to measure the pressure or differential pressure of the fluid flowing in the piping.
Pressure gauges such as pressure quadrature transmitters are installed. These pressure gauges are generally used for the purpose of monitoring plant operating conditions, so they must always maintain the desired accuracy, which is why it is extremely important to properly calibrate pressure gauges. come.

By the way, conventionally, in order to measure the fluid pressure inside the piping in an atomic coupler, as shown in FIG. The pressure indicator 3 is introduced through the pressure indicator 3, and the fluid pressure is obtained from the indicated value of the pressure indicator 3 here.

On the other hand, when calibrating the pressure gauge 1, after connecting the pressure pump 5 and the precision pressure gauge 6 to the pressure gauge 1 via the piping 4,
While the proofreader operates the pressure pump 5 to send air pressure into the piping 4, the proofreader sends out air pressure from the pressure pump 5 so that the measured value of the precision pressure gauge 6 at that time becomes the desired calibration pressure. , record the indicated value of the pressure indicator 3 at this time. This operation of applying pressure for calibration is performed using the pressure gauge 1.
For each measurement range, 0%→100%, 100%→
The measurement is carried out at several points in each range of 0%, and the indicated value of the pressure indicator 3 at that time is sequentially recorded. After that, this measured value is compared with the calibration pressure, and it is determined whether the difference is within a preset allowable accuracy range, and if it is outside the allowable range, the pressure gauge 1 is adjusted. .

(Problems to be Solved by the Invention) However, the following problems have been pointed out in the above-described calibration device.

(1) The proofreader reads the precise measurement value of the precision pressure gauge 6,
Since the pressure pump 5 is operated and the pressure measured by the pressure indicator 3 is recorded, the burden of calibration work is very large.

(2) In addition, since the pressure for calibration is applied from the pressure pump 5 while reading the precise measurement value of the precision pressure gauge 6, and the measured pressure at that time is recorded, the calibration work requires a long time. There is.

(3) Furthermore, when calibrating a pressure meter, it is necessary to judge the maximum positive and negative error from the characteristic curve obtained from the measurement results using a normal meter, so the calibration test The higher the score, the better. However, with conventional calibration equipment, not only does it take a long time to measure each point, but in the case of an atomic couplant equipped with hundreds of pressure gauges 1, the calibration can be divided into 13 parts. There is a problem in that the work time is limited, which naturally limits the number of calibration test scores.

The present invention has been made to solve the above-mentioned problems, and provides a pressure gauge calibration device that can stably supply desired pressure during calibration work and can perform multi-point calibration with high accuracy in a short time. The purpose is to provide

(Means for Solving the Problems) In order to solve the above problems, the pressure gauge calibration device according to the present invention measures the pressure in a plant as shown in FIG.
A pressure measuring means 11 that outputs the pressure measurement signal, a pressure generating means 12 that applies pressure to the pressure measuring means when calibrating the pressure measuring means, and a pressure generating means 12 that measures the pressure generated from the pressure generating means. , a precision pressure measurement means 13 that outputs a precision measurement signal; and a plurality of calibration pressures are set in advance, and the pressure is generated so that the precision measurement signal of the precision pressure measurement means indicates the calibration pressure for each calibration pressure. A pressure control signal for controlling the pressure from the means is supplied to the pressure measuring means, and the pressure 41 is output from the pressure measuring means in accordance with the pressure output from the pressure generating means for each calibration pressure. While storing the pressure measurement signals, the input/output characteristic curve of the pressure measurement means is determined from those pressure measurement signals and the calibration pressure, and this input/output characteristic curve is compared with a predetermined specification characteristic curve of the pressure measurement means. , and control/calculation means 14 for determining the accuracy of the pressure measuring means.

(Function) Therefore, by taking the above-described measures, the present invention sequentially generates pressures corresponding to a plurality of calibration pressures from the pressure generating means when calibrating the pressure measuring means for measuring the pressure in the plant. At the same time as being applied to the pressure measuring means, the pressure applied from the pressure generating means to the pressure measuring means at this time is measured by a precision pressure measuring means, and the pressure measured by this precision pressure measuring means becomes a predetermined calibration pressure. The pressure generated from the pressure generating means is controlled in such a manner. Then, a pressure measurement signal measured by the pressure measurement means for each of the calibration pressures is captured and stored by a control/calculation means, and an input/output characteristic curve of the pressure measurement means is determined from this pressure measurement signal and the calibration pressure; The accuracy of the pressure measuring means is determined from this input/output characteristic curve and a predetermined specification characteristic curve of the pressure measuring means.

(Example) Hereinafter, an example of the apparatus of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of the apparatus of the present invention that performs multi-point calibration for positive region pressure using liquid water pressure. In the figure, reference numeral 21 denotes a pressure gauge as a pressure measuring means installed in the piping of the plant, and this pressure gauge 2
1 is supplied with water pressure for calibration from the control/calculation means 30 via the pressure generation means. This control/calculation means 30 is a part that performs a comparison in advance with a specification characteristic curve and an input/output characteristic curve based on the actual measurement result of the calibration pressure, and performs necessary calculation processing. Control part 3
1 outputs a water pressure control signal corresponding to the water pressure desired to be generated for calibration, and constitutes a part of the pressure generating means.
/A converter 22. This pressure light and generation means include a D/A converter 22 that converts a digital water pressure control signal sent from the arithmetic control unit 31 into an analog water pressure control signal, an electric/water pressure converter 23, a water tank 24, etc. It is configured. This electric/hydraulic pressure converter 23 receives an analog water pressure control signal, generates water pressure corresponding to the water pressure control signal, and applies it to the pressure gauge 21 and precision pressure sensor 25, but the water required for this pressurization is water. It is obtained from tank 24. This precision pressure sensor 25 converts the precision measurement signal corresponding to the water pressure into an analog signal to the A/D converter 2.
6, while the water pressure measurement signal from the pressure gauge 21 is sent to the data processing device 32 of the control and calculation means 30.

The A/D converter 26 receives the precision measurement signal from the precision pressure sensor 25, converts it into a digital signal, and supplies it to the arithmetic control section 31. here.

The calculation control unit 31 compares the calibration pressure and the precision measurement signal,
If there is a deviation, a correction water pressure control signal is sent to the pressure generating means so that the precise measurement signal matches the calibration pressure.

The data processing device 32 stores a plurality of water pressure measurement signals as data, determines an input/output characteristic curve from the obtained data, compares it with a specification characteristic curve, and converts the pressure gauge 2
It is necessary to determine whether or not the pressure gauge 1 is operating within the permissible accuracy range, store the determination result, and adjust the pressure gauge 21 if it is outside the permissible accuracy range. These series of data processing results are displayed on the display 33. Since the information is output as a table or graph to the printer 34, the proofreader can adjust the pressure gauge 21 based on this output.

Reference numeral 27 is an operation unit for setting the calibration pressure and inputting other necessary data to the calculation control unit 31, etc., and 35 is a transmission interface.

Next, the operation of the apparatus configured as above will be explained.

First, when the proofreader sets the calibration pressure for the number of points to be calibrated in advance from the operation unit 27 to the calculation control unit 31, the calculation control unit 3
1, the data is stored in a memory or the like. Pressure gauge 21
When calibration is required, when a start command is input from the operation unit 27 or the like, the arithmetic control unit 31 selects one calibration pressure from a plurality of pre-stored calibration pressures in a predetermined order. Generate a corresponding water pressure control signal. here,
The electric/water pressure converter 23 uses water from the water tank 24 to generate water pressure corresponding to the water pressure control signal sent from the calculation control section 31 via the D/A converter 22, and generates water pressure using the water from the water tank 24. The pressure is applied to the precision pressure sensor 25. Here, the precision pressure sensor 25 obtains a precision measurement signal corresponding to the applied water pressure, and introduces this to the calculation control section 31 via the A/D converter 26. This arithmetic control unit 31 compares the calibration pressure sent to the pressure generating means with the precision measurement signal, and if there is a deviation, generates a correction water pressure control signal to make the deviation zero, and in conjunction with this, the electric - Generate water pressure corresponding to the desired calibration pressure from the water pressure converter 23. When the calibration pressure and the precise measurement signal match, the arithmetic control unit 31 sends a signal to that effect and, if necessary, a precision measurement signal to the data processing device 32 via the transmission interface 35. The data processing device 32 receives a signal from the arithmetic control section 31 indicating that both signals match, takes in the water pressure measurement signal sent from the pressure gauge 21, and stores it in a memory.

The above-described calibration pressure application and correction processing are executed for each calibration point, and each time the water pressure measurement signal output from the pressure gauge 21 is captured and stored in the memory. After that, an input/output characteristic curve is determined using the water pressure measurement signal at each calibration pressure stored in the memory, it is determined whether the pressure gauge 21 is operating within the allowable accuracy range, and the determination result is displayed on the display. 33 and printer 34 as a table or graph. Here, the proofreader adjusts the pressure gauge 21 if the output content of the determination result is outside the allowable accuracy range. In addition,
The content of the determination result can also be stored in memory and output when necessary.

Therefore, according to the embodiments described above, in the past, it was not possible to obtain a large number of calibration points and a lot of time was required for the calibration work, but with this device, the calibration work can be automatically performed in a short time. This makes it possible to quickly calibrate a large number of pressure gauges 21 installed in a plant or the like. Further, since calibration can be performed using a large number of calibration pressures, the pressure gauge 21 can be adjusted accurately.

The relationship between this device and the conventional device will be explained below.

In the conventional calibration device, five target calibration pressures are generated as shown in FIG. 3, and the pressures measured at that time with a pressure gauge are read. In this case, since calibration is performed using a small number of calibration pressures, accurate calibration cannot be performed unless the allowable range shown by arrows in the left and right directions for each calibration point in FIG. 3 is narrowed.

In contrast, with this device, as shown in Figure 4, the original specification characteristic curve of the pressure gauge is compared with the input/output characteristic curve obtained by the calibration test pig, so even if the calibration point deviates to some extent, the calibration test data The characteristic curve can be easily obtained by simply moving on the characteristic curve that should be obtained.

In addition, in conventional calibration equipment, the application of pressure for calibration, the reading of the output of the pressure gauge, and the data organization are all done manually by the proofreader, so the calibration time per pressure gauge is relatively long. Test points are span 0,2 at most
Although it is limited to about 9 points of reciprocation at 5, 50, 75° 100%, this device can obtain calibration test data and input/output characteristic curves of dozens of points in a short time.
Highly accurate calibration can be achieved.

In addition, this device can increase the calibration accuracy of the system without making the generated pressure to be applied highly accurate, so it can be easily calibrated using water, which is extremely difficult to control pressure generation in the past, and it can be used with different types of calibration fluids. can be expanded significantly.

In the above embodiment, the pressure of the pressurized water generated from the electric/hydraulic converter 23 is measured by the precision pressure sensor 25 and corrected, but in addition, for example, as shown in FIG. 28 and an A/D converter 29 are provided, and the temperature signal of the pressurized water is sent to the arithmetic control section 31, where correction is made in accordance with changes in water temperature, thereby achieving even more accurate calibration.

Next, FIG. 6 is a block diagram showing another embodiment of the apparatus of the present invention. The embodiments shown in FIGS. 2 and 5 above mainly allow for other-point calibration of positive region pressure from the 0 point, but the embodiment shown in FIG. 6 has a configuration that also allows other-point calibration of negative region pressure. be. That is, this device is a pressure generating means consisting of a pressurizing device 40, a pressure regulating device 50, etc., and an instrument to be calibrated installed in piping of a plant or the like that measures the pressure generated from this pressure generating means. A pressure gauge 60 such as a pressure quadrature transmitter, a precision pressure sensor 61, and a pressure controller 62. It is constituted by control/calculation means consisting of a servo amplifier 63.

The pressurization device 40 includes a pressure regulator 41 that performs pressure increase control using air pressure as a pressure source, and a pressure increase control from the pressure regulator 41 to increase the pressure of the calibration fluid (water) taken in from the artificial side piping 42. The booster pump 43 outputs a predetermined primary side pressure.

The pressure regulating device 50 controls the primary side pressure from the booster pump 43 based on the output signal of the servo amplifier 63 corresponding to the calibration applied pressure set value button Sv1 from the pressure controller 62 on the side of the calibration piping 51. A servo valve 53 that obtains a calibration pressure 52 and an accumulator 54 that controls the calibration pressure 52 for the purpose of stabilizing the calibration pressure 52 are provided. A servo valve 56 that is controlled based on an output signal from the servo valve 56 and a jet pump 57 that has a function of creating a negative pressure on the back pressure side according to the flow rate of air from the servo valve 56 are provided. In addition, since this pressure regulator 50 uses a nozzle flapper type servo valve 53, residual pressure is generated when the calibration pressure is set to zero.
In order to remove this residual pressure, the servo valve 53 is connected to the back pressure side of the jet pump 57 via a return pipe 58 to enable zero point control.

The pressure controller 62 has a memory, a CPU, etc., and stores in advance the range, withstand pressure, and a plurality of calibrated applied pressure set value patterns sv, sv2, etc. according to the pressure gauge 60. Calibration reference points (target values) etc. are set, and the set value pattern Sv
1. While controlling each servo valve 53, 56 based on SV2, the set value patterns SVI and SV2 are variably corrected using the output P■1 of the precision pressure sensor 61 as the true value, and the output Pv1 of the precision pressure sensor 61 is set as the calibration point. When the pressure is reached, the output Pv2 of the pressure gauge 60 is read and memorized, and after measuring all the calibration pressures, the input/output characteristics of the pressure gauge 60 are determined from the memorized value of the output PV2 of the pressure gauge 60. It has the function of determining the curve and determining the error with the pre-stored specification characteristic curve. Although not shown, a control signal for generating a pressure to be calibrated is input from the pressure controller 62 to the pressure regulator 41.

The servo amplifier 63 uses the calibrated applied pressure set value pattern Sv1. S2 and the output Pv1 of the precision pressure sensor 61 are compared, and the servo valve 53.
It has a function to externally control 56.

Next, the operation of this embodiment will be explained. When calibrating the pressure gauge 60, the plant test valve 60a side is opened, and the meter main valve 60b on the plant piping side is closed. After that, the pressure regulator 41 takes in air pressure and pumps the booster pump 43.
control. Here, the booster pump 43 has a calibration fluid (
Water) is taken in and raised to a predetermined pressure to obtain primary side pressure, which is then supplied to the servo valve 53 of the pressure regulator 50.

On the other hand, the pressure controller 62 performs step S1 in FIG.
As shown in the figure, the range, pressure resistance, and multiple calibration applied pressure setting value patterns, etc. corresponding to the pressure gauge 60 are set in advance from the operation unit (not shown), so one desired calibration applied pressure setting from among them is set. A value pattern is selected, and a set value pattern sv1. When sv2 is output (step S
2. S3. S3'), these setting value patterns sv
1. A signal corresponding to sv2 is applied to servo valves 53 and 56 via servo amplifier 63.

Here, the servo valve 53 controls the primary side pressure from the booster pump 43 to be the calibration pressure 52 equal to the calibration applied pressure set value pattern Sv1, and applies it to the precision pressure sensor 61 and the pressure gauge 60. On the other hand, the servo valve 56 also controls the air flow rate from the pressure regulator 41 to the same set value pattern S2, and marks it on the jet pump 57.]
7 Add. Here, the pressure controller 62 performs step S4.
．． As shown in S4', the output Pv of the precision pressure sensor 61
1 at a predetermined cycle while setting value pattern Sv1.
Compare Sv2 and signal PV, and Pvl is the calibration reference point (
It is determined whether or not the accuracy is within the allowable accuracy range with respect to the standard calibration point). If not, step S3.
Proceed to S3' and perform calibration/correction applied pressure setting value pattern sv,,
Servo amplifier 6 while performing correction processing to vary sv2.
Supply to 3. Servo amplifier 63 is pressure controller 6
Compare the corrected applied pressure set value pattern Sv, S2 obtained from 2 with the output Pvl of the precision pressure sensor 61, and set each servo valve 5 so that the deviation of each becomes zero.
3.56 control. When the output PV1 of the precision pressure sensor 61 falls within the allowable accuracy range of the calibration reference point while performing such control, the pressure controller 62 determines that the predetermined calibration pressure to be calibrated has been reached, and proceeds to step S6. Measure the output PV2 of the pressure gauge 60 as shown, pv,
, pv2, and store it in the memory together with step S7). After performing the above operations with all the calibrated applied pressure setting values and completing all of them, calculate the input/output characteristic curve of the pressure gauge 60 from the stored PV2, and store it separately in advance. A comparison is made with the specified specification characteristic curve, and the error of the pressure gauge 60 is determined.

Therefore, according to the configuration of this embodiment, the servo valve 53.5
6 was used, it is possible to obtain an arbitrary calibration applied pressure that extends not only to the positive region but also to the negative region, and a wide range of calibration can be expected. Furthermore, since the pressure gauge 600 Å output characteristic curve is determined from Pv2, a comprehensive comparison with the specification characteristic curve can be made.

Furthermore, when it is detected from the output of the precision pressure sensor 61 that the calibration point has been reached, the output of the pressure gauge 60 is taken in and an error calculation is performed to obtain an error value, so the pressure gauge 60 can be adjusted immediately. This greatly contributes to improving work efficiency.

In the above embodiment, a nozzle flapper type servo valve 53 was used, but in principle, the downstream pressure leaks to the secondary side and residual pressure is generated, so a jet pump 57 is used to set the zero point. However, the amount of leakage can be sufficiently suppressed by increasing the contact pressure by using a soft material, such as rubber, for the nozzle and flapper. In this case, the eighth
As shown in the figure, a servo valve 59 is provided on the input side of the servo valve 53 without using the jet pump 57, and by lowering the secondary side pressure with this servo valve 59, the output of the servo valve 53, that is, for calibration. Pressure 52 can be synergistically lowered.

(Effects of the Invention) As detailed above, the present invention provides a pressure meter calibration device that can stably supply desired pressure during calibration work and can perform multi-point calibration with high accuracy in a short time. can.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram of a pressure gauge calibration device according to the present invention, Fig. 2 is a configuration diagram as an embodiment for multi-point calibration of positive area pressure, and Figs. A diagram explaining the calibration results of the device of the present invention, FIG. 5 is a configuration diagram explaining a modification of the device in FIG. 2, and FIG. 6 is an example of a pressure gauge calibration device that also allows calibration of negative region pressure. Fig. 7 is an explanatory diagram of the operation for obtaining calibration data, Fig. 8 is a block diagram showing a modification of the device shown in Fig. 6, and Fig. 9 is a block diagram of a conventional pressure gauge calibration device. be. 11...Pressure measuring means, 12...Pressure generating means, 1
3... Precision pressure gauge, 14... Control/calculation means, 15
...Operating means, 21,60.77...Pressure gauge, 2
3... Electricity/pressure converter, 24... Water tank, 25
゜61... Precision pressure sensor, 30... Control/calculation means, 31... Calculation control section, 32... Data processing device, 40... Pressure device, 50... Pressure regulating device, 53.5
6...Sabot valve, 57...Jet pump, 62...
・Pressure controller, 63... Servo amplifier. Applicant's agent Patent attorney Hikoji Suzue Takeshi Q Keye R Takashi = 149-

Claims (1)

[Claims] Pressure measuring means for measuring the pressure in the plant and outputting the pressure measurement signal; Pressure generating means for applying pressure to the pressure measuring means when calibrating the pressure measuring means;
Precision pressure measurement means that measures the pressure generated from this pressure generation means and outputs a precision measurement signal, and a plurality of calibration pressures are set in advance, and a precision measurement signal of the precision pressure measurement means is set for each calibration pressure. supplying a pressure control signal to the pressure measuring means to control the pressure from the pressure generating means so as to indicate the calibration pressure, and responding to the pressure output from the pressure generating means for each calibration pressure. The pressure measurement signals outputted from the pressure measurement means are stored, and the input/output characteristic curve of the pressure measurement means is determined from these pressure measurement signals and the calibration pressure, and the input/output characteristic curve and the preset pressure measurement A pressure meter calibration device comprising control/calculation means for determining the accuracy of the pressure measuring means by comparing the means with a specification characteristic curve of the means.