JP6928705B2 - Measuring system, measuring method and pressure measuring device - Google Patents

Description

The present disclosure relates to a measuring system, a measuring method and a pressure measuring device for measuring pressure.

Conventionally, a pressure measuring device that measures a pressure based on the output of a pressure sensor is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2005-164406

The pressure measuring device may be inspected or calibrated to check the condition of the device. The inspection and calibration are performed on a plurality of pressure measuring devices based on, for example, one pressure measuring device.

It is an object of the present disclosure to provide a measuring system, measuring method and pressure measuring device capable of performing inspection or calibration with higher accuracy.

The measuring system according to some embodiments includes a plurality of pressure measuring devices capable of measuring pressure, and the plurality of pressure measuring devices measure pressure at a timing specified by a trigger signal that specifies the timing of measurement. do. In this way, the measurement timings of the plurality of pressure measuring devices can be synchronized by measuring the pressure at the timing specified by the trigger signal by the plurality of pressure measuring devices. Therefore, the pressure measurement result by the plurality of pressure measuring devices is less affected by the difference in the pressure of the fluid according to the timing of performing the pressure measurement. As a result, inspection or calibration can be performed with higher accuracy.

In one embodiment, the trigger signal may be generated by any one of the plurality of pressure measuring devices. In this way, by generating the trigger signal by any one of the plurality of pressure measuring devices provided in the measuring system, the measuring system synchronizes the measurement timing without using an external device as a source of the trigger signal. Can be done.

In one embodiment, the trigger signal may be transmitted from an external device to the plurality of pressure measuring devices. By supplying the trigger signal from an external device in this way, it is possible to synchronize the measurement timings of the plurality of pressure measuring devices without imposing a load on the process of generating the trigger signal.

In one embodiment, each of the plurality of pressure measuring devices may include a trigger input switching unit that switches the input source of the trigger signal between an internal trigger generation unit and an external device. As described above, since the pressure measuring device includes the trigger input switching unit, the input source of the trigger signal can be easily switched by performing the switching in the trigger input switching unit.

In one embodiment, the plurality of pressure measuring devices may be daisy-chained. By connecting the plurality of pressure measuring devices in a daisy chain in this way, the trigger signal is sequentially transmitted to the plurality of pressure measuring devices.

The measuring method according to some embodiments is a measuring method executed by a measuring system including a plurality of pressure measuring devices capable of measuring pressure, wherein the plurality of pressure measuring devices triggers to specify a measurement timing. The step of receiving the signal and the step of the plurality of pressure measuring devices measuring the pressure at the timing specified by the trigger signal are included. In this way, the measurement timings of the plurality of pressure measuring devices can be synchronized by measuring the pressure at the timing specified by the trigger signal by the plurality of pressure measuring devices. Therefore, the pressure measurement result by the plurality of pressure measuring devices is less affected by the difference in the pressure of the fluid according to the timing of performing the pressure measurement. As a result, inspection or calibration can be performed with higher accuracy.

The pressure measuring device according to some embodiments is designated by the trigger input switching unit that switches the input source of the trigger signal that specifies the measurement timing between the internal trigger generation unit and the external device, and the trigger signal. It includes a control unit that executes a pressure measurement process at a timing. As described above, since the pressure measuring device includes the trigger input switching unit, the input source of the trigger signal can be easily switched by performing the switching in the trigger input switching unit. As a result, when the pressure measuring device is connected to another pressure measuring device, a trigger signal is transmitted and received, and the pressure is measured at the timing specified by the trigger signal to measure the measurement timing of a plurality of pressure measuring devices. Can be synchronized. Therefore, the pressure measurement result by the plurality of pressure measuring devices is less affected by the difference in the pressure of the fluid according to the timing of performing the pressure measurement. As a result, inspection or calibration can be performed with higher accuracy.

According to the present disclosure, it is possible to provide a measuring system, a measuring method and a pressure measuring device capable of performing inspection or calibration with higher accuracy.

It is the schematic which shows an example of the measurement system. It is a functional block diagram which shows an example of the schematic structure of the pressure measuring device. It is a figure explaining an example of the inspection or calibration process using the measurement system of FIG. It is the schematic which shows an example of the measurement system which concerns on one Embodiment. It is a functional block diagram in one modification of a measurement system. It is the schematic which shows an example of the measurement system used in an experiment. It is a figure which shows the measured value of the input pressure by the reference device and the inspected device when the trigger signal is not used in the 1st experiment. It is a figure which shows the difference of the measured value of the reference device and the device to be inspected shown in FIG. 7. It is a figure which shows the measured value of the input pressure by the reference device and the inspected device when the trigger signal is used in the 1st experiment. It is a figure which shows the difference of the measured value of the reference device and the device to be inspected shown in FIG. It is a figure which shows the change of the input pressure of the fluid supplied to the pressure pipe in the 2nd experiment. It is a figure which shows the difference of the measured value of the reference device and the inspected device when the trigger signal is not used in the 2nd experiment. It is a figure which shows the difference of the measured value of the reference device and the inspected device when the trigger signal is used in the 2nd experiment. It is a figure which shows typically the state when the measurement system is applied to the field calibration. It is a figure explaining one response example of a measurement system.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing an example of a measurement system. The measuring system 10 shown in FIG. 1 includes a control device 100, a pressure control device 110, three pressure measuring devices 120, 121 and 122, and an atmospheric pressure gauge 130. In the measuring system 10 shown in FIG. 1, pressure is measured by three pressure measuring devices 120, 121 and 122. By comparing the results of pressure measurement by these three pressure measuring devices 120, 121 and 122, the pressure measuring device 120, 121 or 122 is inspected and calibrated.

In the example shown in FIG. 1, the pressure measuring device 120 is a reference device used as a reference for inspection or calibration, and the other pressure measuring devices 121 and 122 are devices to be inspected or calibrated. .. That is, in the measuring system 10 shown in FIG. 1, the pressure measuring devices 121 and 122 are inspected or calibrated with the pressure measuring device 120 as a reference. Hereinafter, in the present specification, the pressure measuring device used as a reference for inspection or calibration is also referred to as a "reference device", and the pressure measuring device to be inspected or calibrated is also referred to as an "inspected device". When distinguishing between the two inspected devices in the measurement system 10, they are hereinafter referred to as "first inspected device 121" and "second inspected device 122". The three pressure measuring devices 120, 121 and 122 may be configured as, for example, a pressure transmitter or a differential pressure transmitter.

In the measurement system 10, a pressure pipe is connected to the reference device 120 and the devices 121 and 122 to be inspected as shown by a solid line in FIG. A fluid such as gas is supplied to the pressure pipe. The fluid supplied to the pressure pipe is controlled by the pressure control device 110 based on, for example, a control signal from the control device 100. When inspection or calibration is performed in the measuring system 10, the reference device 120 and the devices 121 and 122 to be inspected measure the pressure of the fluid supplied to the pressure pipe, respectively. Inspection or calibration is performed by comparing the pressure measurement results of the reference device 120 and the devices 121 and 122 to be inspected. Although an example in which the measurement system 10 includes two devices 121 and 122 to be inspected is shown here, the number of devices to be inspected does not necessarily have to be two. The measurement system 10 may include, for example, one device to be inspected or three or more devices to be inspected.

The control device 100 controls and manages the entire inspection or calibration process in the measurement system 10. The control device 100 is composed of, for example, a computer device. The control device 100 is communicably connected to each of the pressure control device 110, the reference device 120, the inspected devices 121 and 122, and the atmospheric pressure gauge 130, for example, as shown by the broken line in FIG. The control device 100 acquires and controls data by transmitting and receiving signals to and from each of the pressure control device 110, the reference device 120, the inspected devices 121 and 122, and the atmospheric pressure gauge 130, which are communicably connected. It can send signals.

The pressure control device 110 controls the fluid supplied to the pressure pipe. The pressure control device 110 may be composed of, for example, a pressure controller, a weight-shaped pressure balance, or the like. For example, when the pressure measuring devices 120, 121 and 122 are configured by a pressure transmitter and the range of 1 kPa is to be detected with an accuracy of 0.01% or less, a weight-shaped pressure balance is used as the pressure control device 110. good. On the other hand, for example, when the pressure measuring devices 120, 121 and 122 are configured by a differential pressure transmitter and the range of 1 kPa is to be detected with an accuracy of 0.1% or less, a pressure controller is used as the pressure control device 110. good.

For example, on the upstream side of the pressure control device 110, that is, on the fluid supply source side, a device for compressing the fluid such as a compressor is provided as a pressure source. The pressure control device 110 controls the pressure of the fluid input from the compressor and supplies it to the pressure pipe. For example, the pressure control device 110 stabilizes the pressure of the fluid whose pressure is unstable and is input from the compressor and supplies it to the pressure pipe.

The measurement system 10 may include a plurality of pressure control devices 110. The plurality of pressure control devices 110 may have different output pressure ranges. In this case, one pressure control device 110 is selected from the plurality of pressure control devices 110 according to the specifications of the devices 121 and 122 to be inspected or calibrated, the conditions for inspection or calibration, the state of the pressure control device 110, and the like. , The selected pressure control device 110 may be used to supply fluid to the pressure pipe.

The reference device 120 and the devices 121 and 122 to be inspected are composed of a pressure measuring device and measure a gauge pressure. FIG. 2 is a functional block diagram showing an example of a schematic configuration of a pressure measuring device. The reference device 120 and the devices 121 and 122 to be inspected may all be configured as the pressure measuring device 140 shown as an example in FIG. The pressure measuring device 140 includes a pressure detecting unit 141, a control unit 142, a storage unit 143, a communication unit 144, a display unit 145, and an input unit 146.

The pressure detection unit 141 is a pressure sensor that detects the pressure of the fluid input to the pressure measuring device 140. The pressure detection unit 141 generates an electric signal corresponding to the detected pressure and transmits it to the control unit 142. For example, the pressure detection unit 141 generates an electric signal by converting the pressure into an electric signal having a natural frequency using a silicon resonant pressure sensor.

The control unit 142 controls and manages the entire pressure measuring device 140, including each functional block of the pressure measuring device 140. The control unit 142 is configured as software executed on an arbitrary suitable processor such as a CPU (Central Processing Unit) that executes a program that defines a control procedure, or is configured by a dedicated processor specialized for each process. Can be done. Such a program is stored in, for example, a storage unit 143, an external storage medium connected to the pressure measuring device 140, or the like.

The control unit 142 calculates the pressure of the fluid supplied to the pressure measuring device 140 based on the electric signal acquired from the pressure detecting unit 141. For example, the control unit 142 can count the frequency of the signal output from the pressure detection unit 141 and perform a preset calculation to calculate the pressure. In this way, the pressure measured by the pressure measuring device 140 is calculated.

The storage unit 143 may be composed of a semiconductor memory, a magnetic memory, or the like. The storage unit 143 stores various information, a program for operating the pressure measuring device 140, and the like. The storage unit 143 may also function as a work memory.

The communication unit 144 transmits and receives signals to and from an external device based on the control of the control unit 142. For example, the communication unit 144 transmits a signal related to the measured pressure calculated by the control unit 142 to the control device 100. In this way, the pressure measuring device 140 can transmit the measured pressure to the control device 100.

The display unit 145 is composed of a well-known display such as a liquid crystal display (LCD), an organic EL display (OELD: Organic Electro-Luminescence Display), or an inorganic EL display (IELD: Inorganic Electro-Luminescence Display). Display device. Information on the measured pressure calculated by, for example, the control unit 142 is displayed on the display unit 145. That is, on the display unit 145, for example, a value as a pressure measurement result by the reference device 120 and a value as a pressure measurement result by the inspected devices 121 and 122 are displayed.

The input unit 146 receives an operation input from the user of the pressure measuring device 140, and is composed of, for example, an operation button (operation key). The input unit 146 may be configured by a touch screen, and an input area for receiving operation input from the user may be displayed on a part of the display device which is the display unit 145 to accept the touch operation input by the user.

The pressure measuring device 140 described with reference to FIG. 2 is an example, and the pressure measuring device 140 does not necessarily have the same configuration as the configuration described here. For example, the pressure measuring device 140 may include other configurations and may not include a part of the configurations shown in FIG. For example, the pressure measuring device 140 may not include the display unit 145. In this case, the pressure measuring device 140 may transmit the pressure measurement result to the control device 100. The control device 100 may display information on the measurement result of the transmitted pressure on the display unit included in the control device 100.

The atmospheric pressure gauge 130 measures the atmospheric pressure. The atmospheric pressure measured by the atmospheric pressure gauge 130 is used as a reference pressure when calculating the measured pressure in the reference device 120 and the devices 121 and 122 to be inspected.

The measurement system 10 may include an absolute pressure gauge together with the atmospheric pressure gauge 130 or in place of the atmospheric pressure gauge 130. The absolute pressure gauge measures absolute pressure (also called absolute pressure). The absolute pressure measured by the absolute pressure gauge may be used as a reference pressure when calculating the measured pressure in the reference device 120 and the devices 121 and 122 to be inspected.

FIG. 3 is a diagram illustrating an example of inspection or calibration processing using the measurement system 10 of FIG. The inspection or calibration process may be performed, for example, in a so-called homeothermic environment where air conditioning is controlled. When measuring the pressure, the temperature fluctuation of the surrounding environment may affect the fluctuation of the input pressure of the fluid supplied to the pressure pipe, but the use of a thermostatic chamber makes it easier to suppress the fluctuation of the input pressure.

When the inspection or calibration process is performed, the pressure control device 110 controls the flow rate of the fluid supplied to the pressure pipe as described above. However, it is difficult to constantly control the pressure even by controlling the pressure control device 110. That is, for example, as schematically shown in FIG. 3, the pressure of the fluid supplied to the pipe also fluctuates even by the control by the pressure control device 110.

The reference device 120 and the devices 121 and 122 to be inspected perform measurement of the supplied pressure, for example, at predetermined sampling cycles, respectively. In the example of FIG. 3, for example, the reference device 120 measures the pressure at the _{times TS1} and _{TS2 , the first device 121 measures the pressure at the times TA1} and _TA2 , and the second device to be inspected. 122 measures the pressure at _{times TB1} and _TB2. In this way, the reference device 120, the first device to be inspected 121, and the second device to be inspected 122 can measure the pressure at different timings. In this case, since the pressure of the fluid fluctuates, the pressure of the fluid differs depending on the timing at which the pressure is measured. Therefore, even if the pressure values measured by the reference device 120, the first device 121, and the second device 122 are compared, the pressure of the fluid itself may differ if the timing at which the pressure is measured is different. It is difficult to accurately inspect or calibrate due to the difference in fluid pressure according to the timing of measurement.

In order to reduce the influence of the pressure difference of the fluid according to the timing at which the pressure is measured, for example, the pressure is applied at a plurality of timings for each of the reference device 120, the first inspected device 121, and the second inspected device 122. Inspection or calibration may be performed by measuring, calculating the average value and / or standard deviation of the measured pressure, and comparing the average value and / or standard deviation. However, by using the average value and / or standard deviation of the pressure, the influence of the pressure difference of the fluid according to the timing of measuring the pressure can be reduced, but the timing of the pressure measurement is still different, and the inspection is performed. Or, there is a limit to improving the accuracy of calibration.

Further, when the measuring system 10 includes a plurality of pressure control devices 110 in order to secure a wide pressure range in inspection or calibration, the larger the number of pressure control devices 110, the higher the cost of the measuring system 10.

As a method for suppressing pressure fluctuations, after supplying fluid to the pressure pipe by the pressure control device 110, the valve on the input side (upstream side) of the pressure pipe is closed to confine the fluid in the pressure pipe, and inside the pressure pipe. It is also possible to wait for the pressure of the fluid to stabilize before measuring the pressure with the pressure measuring devices 120, 121 and 122. However, since this method traps the fluid in the pressure pipe, it is easily affected by changes in the ambient temperature. That is, in this method, when the ambient temperature changes, the fluid in the pressure pipe expands or contracts, and the pressure in the pressure pipe tends to change. Therefore, if an inspection or calibration is to be performed with higher accuracy by this method, it is necessary to perform the inspection or calibration in a homeothermic environment. When using a homeothermic chamber, equipment costs for the homeothermic chamber are required.

Further, when the pressure measuring devices 120, 121 and 122 are configured by a pressure transmitter and the differential pressure inspection of the pressure transmitter is performed, the differential pressure is generated by using two weight-shaped pressure balances to perform the inspection. be able to. However, since the operation of the weight-shaped pressure balance requires a certain skill, it is not easy for everyone to handle, and the time required for the operation may increase the inspection time. In addition, weight-shaped pressure balances may be expensive depending on their specifications, and the cost for inspection or calibration may be high.

Further, when the pressure measuring devices 120, 121 and 122 are configured by a differential pressure transmitter and the differential pressure transmitter is inspected or calibrated, it is necessary to perform the inspection or calibration in a place where air conditioning is not controlled. Therefore, during inspection or calibration, it is easily affected by fluctuations in the surrounding environment such as atmospheric pressure or temperature, and it is difficult to improve the accuracy of inspection or calibration.

Therefore, in the present disclosure, a measuring system, a measuring method, and a pressure measuring device capable of performing inspection or calibration with higher accuracy will be described.

FIG. 4 is a schematic view showing an example of the measurement system 20 according to the embodiment. The measuring system 20 according to the present embodiment includes a control device 200, a pressure control device 210, three pressure measuring devices 220, 221 and 222, and an atmospheric pressure gauge 230.

In the present embodiment, the pressure measuring device 220 is a reference device used as a reference for inspection or calibration, and the other pressure measuring devices 221 and 222 are devices to be inspected or calibrated. Therefore, in the present embodiment, the pressure measuring device 220 is the reference device, and the pressure measuring devices 221 and 222 are the devices to be inspected. When distinguishing between the two inspected devices, they are hereinafter referred to as "first inspected device 221" and "second inspected device 222". The three pressure measuring devices 220, 221 and 222 may be configured as, for example, a pressure transmitter or a differential pressure transmitter.

In the measurement system 20 according to the present embodiment, a pressure pipe is connected to the reference device 220 and the devices to be inspected 221 and 222 as shown by a solid line in FIG. The fluid controlled by the pressure control device 210 is supplied to the pressure pipe. When inspection or calibration is performed in the measuring system 20, the reference device 220 and the devices 221 and 222 to be inspected measure the pressure of the fluid supplied to the pressure pipe, respectively. Inspection or calibration is performed by comparing the pressure measurement results of the reference device 220 and the devices 221 and 222 to be inspected. The number of devices to be inspected included in the measurement system 20 does not necessarily have to be two, and the measurement system 20 may include, for example, one device to be inspected or three or more devices to be inspected.

In the measurement system 20 according to the present embodiment, as shown in FIG. 4, the pressure control device 210, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 are provided. For example, it is connected in a daisy chain by a cable or the like. The pressure control device 210, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 are an input terminal for receiving a signal input, an output terminal for outputting a signal, or an output terminal for outputting a signal. It has both. That is, the pressure control device 210, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 output a signal from the output terminal to the cable and transmit the signal via the cable. The input of the signal is received from the input terminal. In this embodiment, a trigger signal described later is transmitted via a cable. The pressure control device 210, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 do not necessarily have to be daisy-chained by using a cable. If the pressure control device 210, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 are connected by wire or wirelessly so as to be able to receive the trigger signal. good.

The pressure control device 210 has the same configuration and function as the pressure control device 110 described with reference to FIG. For example, the pressure control device 210 controls the fluid supplied to the pressure pipe. The pressure control device 210 according to the present embodiment further outputs a signal for designating the measurement timing to the cable connected in the daisy chain. Hereinafter, the signal that specifies the measurement timing is also referred to as a "trigger signal" in the present specification. That is, in the present embodiment, the pressure control device 210 includes a trigger signal generation unit that generates a trigger signal.

The trigger signal output from the pressure control device 210 is sequentially transmitted to the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 via a cable connected in a daisy chain. .. Specifically, the trigger signal output from the output terminal of the pressure control device 210 is input from the input terminal of the reference device 220 via a cable. The reference device 220 that has received the input of the trigger signal outputs the trigger signal from the output terminal. The output signal is input from the input terminal of the first inspected device 221 via a cable. In this way, the trigger signal is transmitted from the reference device 220 in the order of the first device to be inspected, the second device to be inspected 222, and the atmospheric pressure gauge 230. The reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 measure the pressure at the timing specified by the trigger signal. That is, the trigger signal can synchronize the pressure measurement timing by the reference device 220, the first device to be inspected, the second device to be inspected 222, and the atmospheric pressure gauge 230.

The trigger signal may specify, for example, the timing at which the pressure measurement is started. In this case, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 start measuring the pressure at the timing specified by the trigger signal, and then the pressure is measured at a predetermined sampling cycle. To measure. If the sampling cycles of the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 are equal, these devices can measure the pressure at the same timing.

The trigger signal may specify when to perform the pressure measurement. In this case, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 execute the pressure measurement at the timing specified by the trigger signal. In this case, the pressure control device 210 may transmit a trigger signal at a predetermined sampling cycle. In this case, even if the sampling cycles of the reference device 220, the first device to be inspected, the second device to be inspected 222, and the atmospheric pressure gauge 230 are different, the measurement timings should be synchronized. Can be done.

When the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 finish measuring the pressure, the measurement results are temporarily stored in the storage unit provided in each device.

Since the configuration and function of the control device 200 has the same configuration and function as the control device 100 described with reference to FIG. 1, detailed description thereof will be omitted. Further, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 each transmit and receive the above-mentioned trigger signal and measure based on the trigger signal, respectively. Since it is the same as the reference device 120, the first device to be inspected 121, the second device to be inspected 122, and the atmospheric pressure gauge 130 described with reference to FIG. 1, detailed description thereof will be omitted.

According to the measurement system 20 according to the present embodiment, the pressure control device 210 outputs a trigger signal for designating the measurement timing, and the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmosphere. The pressure gauge 230 measures the pressure at the timing specified by the trigger signal. As a result, even if the pressure of the fluid input to the pressure pipe is not stable, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 have the same timing. Since the pressure is measured in the above, the pressure measurement results by these devices are less affected by the difference in the pressure of the fluid according to the timing of the pressure measurement as described with reference to FIG. Therefore, according to the measurement system 20 according to the present embodiment, the inspection or calibration can be performed with higher accuracy than the measurement system 10 described with reference to FIG.

Further, according to the measurement system 20 according to the present embodiment, inspection or calibration can be performed with higher accuracy even if the pressure of the fluid input to the pressure pipe is not stable. Therefore, refer to FIG. Compared with the measurement system 10 described, the ambient conditions required for performing the inspection or calibration process can be relaxed. That is, according to the measurement system 20 according to the present embodiment, for example, the required ambient temperature range is wider than that of the measurement system 10. Therefore, according to the measurement system 20, it is possible to eliminate the need for air-conditioning equipment when performing inspection or calibration processing, or to relax the operating conditions even when the air-conditioning equipment is used. As a result, according to the measurement system 20 according to the present embodiment, capital investment can be reduced. Further, according to the measurement system 20 according to the present embodiment, inspection or calibration can be performed without waiting until the pressure of the fluid in the pressure pipe stabilizes.

Further, according to the measurement system 20 according to the present embodiment, the trigger signal is also supplied to the atmospheric pressure gauge 230 and the measurement timing is synchronized, so that the reference device 220, the first device to be inspected 221 and the second device to be inspected are synchronized. The timing of the gauge pressure measurement by 222 and the atmospheric pressure measurement by the atmospheric pressure gauge 230 can be synchronized.

Further, in the present embodiment, since the trigger signal is generated by the pressure control device 210, the timing of pressure measurement can be synchronized without requiring an external trigger signal generator for generating the trigger signal. can.

In the above embodiment, an example in which the pressure control device 210 generates a trigger signal has been described. However, the trigger signal does not necessarily have to be generated by the pressure control device 210. For example, the trigger signal may be generated by any of the reference device 220, the first device to be inspected, the second device to be inspected 222, and the atmospheric pressure gauge 230, and may be transmitted to another device. The trigger signal is a trigger signal for a device that synchronizes the timing of pressure measurement (for example, in the example shown in FIG. 4, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230). It may be generated by any device capable of supplying. Even when a trigger signal is supplied from such a device, the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230 can measure the pressure at the same timing. Therefore, it is less likely to be affected by the pressure difference of the fluid according to the timing of pressure measurement, and inspection or calibration can be performed with higher accuracy. Further, when the trigger signal is generated by the device included in the measurement system 20 (for example, any of the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230), the measurement system 20 Can synchronize the measurement timing without using an external device that is a source of the trigger signal.

For example, the trigger signal may be generated by an external device of the measurement system 20 shown in FIG. 4 and supplied to the reference device 220, the devices 221 and 222 to be inspected, and the atmospheric pressure gauge 230. When the trigger signal is supplied from an external device, the device included in the measurement system 20 (for example, one of the reference device 220, the first device to be inspected 221 and the second device to be inspected 222, and the atmospheric pressure gauge 230). , The measurement timing can be synchronized without imposing a load on the process of generating the trigger signal.

Further, for example, the trigger signal may be generated by the control device 200 and supplied to the reference device 220, the devices to be inspected 221 and 222, and the atmospheric pressure gauge 230. Further, for example, the trigger signal may be generated by the reference device 220, the device to be inspected 221 or 222, or the atmospheric pressure gauge 230.

FIG. 5 is a functional block diagram of a modified example of the measurement system. FIG. 5 shows the control device 300, the reference device 310, and the device to be inspected 311 included in the measurement system 30, and the description is omitted for other constituent devices such as the pressure control device and the atmospheric pressure gauge. Has been done. Further, in FIG. 5, functional blocks are shown only for the reference device 310 and the device to be inspected 311. In the measurement system 30 shown in FIG. 5, the reference device 310 or the device to be inspected 311 is configured to be able to generate a trigger signal.

As shown in FIG. 5, the reference device 310 and the device to be inspected 311 may have the same functional block. Therefore, here, the functional block included in the reference device 310 will be described, and the description of the functional block included in the inspected device 311 will be omitted.

The reference device 310 includes a pressure detection unit 341, a control unit 342, a storage unit 343, a communication unit 344, a display unit 345, an input unit 346, and a trigger control unit 347. The configurations and functions of the pressure detection unit 341, the control unit 342, the storage unit 343, the communication unit 344, the display unit 345, and the input unit 346 are described with reference to FIG. 2, respectively, with reference to the pressure detection unit 141 and the control unit 142. , The storage unit 143, the communication unit 144, the display unit 145, and the input unit 146 are the same, and therefore detailed description thereof will be omitted here.

The reference device 310 includes a trigger control unit 347. The trigger control unit 347 manages the generation and transmission of the trigger signal. The trigger control unit 347 is connected to the input terminal and the output terminal of the trigger signal. Therefore, when the reference device 310 receives the input of the trigger signal from the input terminal, the trigger signal is input to the trigger control unit 347. Further, a trigger signal is output from the trigger control unit 347 to the output terminal. The trigger control unit 347 includes an internal trigger generation unit 348 and a trigger input switching unit 349.

The internal trigger generation unit 348 generates a trigger signal. For example, the internal trigger generation unit 348 generates a trigger signal at a predetermined cycle.

The trigger input switching unit 349 includes a switching device that switches the input source of the trigger signal. The trigger input switching unit 349 includes a first input unit 351 and a second input unit 352, and an output unit 353. The first input unit 351 is connected to the internal trigger generation unit 348. The second input unit 352 is connected to an input terminal in which the reference device 310 receives an input of a trigger signal from an external device. The output unit 353 is connected to an output terminal that outputs a trigger signal.

The trigger input switching unit 349 selectively switches between the first input unit 351 and the second input unit 352, thereby switching the input source of the trigger signal between the internal trigger generation unit 348 and the external device. The switching is performed based on, for example, the control signal of the control unit 342. When the first input unit 351 is selected by the trigger input switching unit 349 of the reference device 310, the reference device 310 functions as a trigger signal generation source in the measurement system 30. In this case, the trigger signal generated by the internal trigger generation unit 348 of the reference device 310 is supplied to the control unit 342, and the control unit 342 measures the pressure at the timing specified by the trigger signal. Further, in this case, the trigger signal generated by the internal trigger generation unit 348 of the reference device 310 is output to the outside from the output terminal via the output unit 353. For example, as shown in FIG. 5, when the second input unit 352 is selected in the trigger input switching unit 349 of the inspected device 311, the inspected device 311 generates and outputs a trigger signal by the reference device 310. Accepts input. The device to be inspected 311 measures the pressure at the timing specified by the trigger signal that receives the input. The device to be inspected 311 can output the trigger signal that has received the input from the output terminal to the outside via the output unit 353.

In this way, the reference device 310 and the device to be inspected 311 internally switch the input source of the trigger signal by switching between the first input unit 351 and the second input unit 352 in the trigger input switching unit 349. Or it can be switched to the outside. Further, by using the reference device 310 and the device to be inspected 311 provided with the trigger control unit 347 in this way, the input source of the trigger signal can be easily switched by performing switching.

The inventors of the measurement system according to the present disclosure conducted two experiments in order to verify the effect of the measurement system. FIG. 6 is a schematic view showing the measurement system 40 used in the experiment. The measurement system 40 includes a control device 400, a pressure control device 410, a reference device 420, an inspected device 421, and an atmospheric pressure gauge 430. The configurations and functions of the control device 400, the pressure control device 410, the reference device 420, the inspected device 421, and the atmospheric pressure gauge 430 are described with reference to FIG. 4, respectively, the control device 200, the pressure control device 210, and the reference device 220, respectively. , The first device to be inspected 221 and the atmospheric pressure gauge 230. In the experiment, a digital pressure gauge "MT210" manufactured by Yokogawa Electric Corporation was used as the reference device 420, the device to be inspected 421, and the atmospheric pressure gauge 430.

In the first experiment, the pressure control device 410 was set to supply 1 kPa of fluid to the pressure pipe. In the first experiment, the inventors verified the difference in the measured pressure between the reference device 420 and the device to be inspected 421 in the measurement system 40 shown in FIG. 6 with and without the trigger signal.

FIG. 7 is a diagram showing the measured values of the input pressure of the pressure pipe by the reference device 420 and the inspected device 421 when the trigger signal is not used in the first experiment. FIG. 8 is a diagram showing the difference between the measured values of the reference device 420 and the device to be inspected 421 shown in FIG. 7. When the trigger signal is not used, the pressure measurement timing by the reference device 420 and the inspected device 421 may shift. In this case, as can be understood from FIG. 8, the difference between the measured values of the reference device 420 and the device to be inspected 421 may deviate significantly.

FIG. 9 is a diagram showing the measured values of the input pressure of the pressure pipe by the reference device 420 and the inspected device 421 when the trigger signal is used in the first experiment. FIG. 10 is a diagram showing the difference between the measured values of the reference device 420 and the device to be inspected 421 shown in FIG. When the trigger signal is used, the pressure measurement timings by the reference device 420 and the inspected device 421 are synchronized. In this case, as can be understood from FIG. 10, the difference between the measured values of the reference device 420 and the device to be inspected 421 is within a certain range. In particular, referring to FIG. 9, there is a place where the pressure of the fluid supplied to the pressure pipe becomes unstable and the value of the pressure detected by the reference device 420 and the device to be inspected 421 fluctuates. Even in this case, it was confirmed that the difference between the measured values of the reference device 420 and the inspected device 421 was within a predetermined range as shown in FIG. Therefore, it can be said that the difference (instrumental error) for each measuring instrument can be compared within a certain width by synchronizing the pressure measurement timing between the reference device 420 and the inspected device 421 by the trigger signal.

In the second experiment, the pressure of the fluid supplied to the pressure pipe by the pressure control device 410 was set to be changed from 0 kPa to 130 kPa. In this way, a state in which the pressure input fluctuates was generated in a pseudo manner. In the second experiment, the inventors verified the difference in the measured pressure between the reference device 420 and the device to be inspected 421 in the measurement system 40 shown in FIG. 6 with and without the trigger signal.

FIG. 11 is a diagram showing a change in the input pressure of the fluid supplied to the pressure pipe in the second experiment. As shown in FIG. 11, the pressure of the fluid supplied to the pressure pipe was set to be changed from 0 kPa to 130 kPa. In the second experiment, the inventors set the input condition to be 130 kPa / 100 s.

FIG. 12 is a diagram showing the difference between the measured values of the input pressure of the pressure pipe by the reference device 420 and the inspected device 421 when the trigger signal is not used in the second experiment. As can be seen from FIG. 12, when the trigger signal is not used, the difference between the measured values of the reference device 420 and the inspected device 421 may deviate significantly.

FIG. 13 is a diagram showing the difference between the measured values of the input pressure of the pressure pipe by the reference device 420 and the inspected device 421 when the trigger signal is used in the second experiment. As can be seen from FIG. 13, when the pressure measurement timing is synchronized using the trigger signal, the difference between the measured values of the reference device 420 and the inspected device 421 is within a certain range. When compared with FIG. 12, the range of the difference between the measured values of the reference device 420 and the inspected device 421 when the trigger signal is used is extremely small as compared with the case where the trigger signal is not used. Understood. In this way, even when the input pressure fluctuates, it can be said that the accuracy of measurement or calibration can be improved by synchronizing the measurement timing.

The measurement system according to the above-described embodiment can also be applied to field calibration performed at the site where the device to be inspected is installed. For example, field calibration of differential pressure transmitters and / or pressure transmitters is performed outdoors. In this case, for example, as schematically shown in FIG. 14, a worker or the like performing calibration uses the hand pump 50 and the pressure calibrator 51 as a reference device, and the differential pressure / pressure transmitter 52 which is an inspected device. Carry it to the place where it was installed. The pressure calibrator 51 is connected to the pressure pipe to which the differential pressure / pressure transmitter 52 is connected so that the input of the pressure of the pressure pipe can be received. Further, the pressure calibrator 51 and the differential pressure / pressure transmitter 52 are connected to each other so as to be able to communicate with each other. The fluid in the pressure pipe to which the pressure calibrator 51 and the differential pressure / pressure transmitter 52 are connected is pressurized by the hand pump 50. The pressure calibrator 51 and the differential pressure / pressure transmitter 52 each measure the pressure. At this time, the pressure calibrator 51 and the differential pressure / pressure transmitter 52 measure the pressure at the timing specified by the trigger signal. The trigger signal is generated by, for example, the pressure calibrator 51 and output to the differential pressure / pressure transmitter 52. The electric signal related to the pressure measured by the differential pressure / pressure transmitter 52 is transmitted to, for example, the pressure calibrator 51. Calibration is performed by comparing the pressure values measured by the pressure calibrator 51 and the differential pressure / pressure transmitter 52, respectively.

Here, in the field calibration, the fluid in the pressure pipe may fluctuate slowly under the influence of the ambient temperature. However, by applying the measurement system according to the present embodiment, the accuracy of calibration can be improved by synchronizing the measurement timings even in an environment where the input pressure can fluctuate.

The measurement system according to the above-described embodiment can be applied to measurements other than pressure, for example. The measurement system described above can be used when the measurement timings of a plurality of measuring instruments are synchronized. For example, the measurement system described above can be applied to a flow rate measurement system. For example, as schematically shown in FIG. 15, in the test of the cooling / heating capacity of the air conditioner 60, the differential pressure before and after the air volume measuring nozzle 61 may be measured. In the measurement of the differential pressure, the gauge pressure inside the air conditioner 60 is measured by the first measuring instrument 62 on the upstream side of the air volume measuring nozzle 61, and the air conditioner by the second measuring instrument 63 on the downstream side of the air volume measuring nozzle 61. The differential pressure inside the conditioner 60 is measured. In the test of the cooling / heating capacity of the air conditioner 60, the measurement timing by the first measuring instrument 62 and the second measuring instrument 63 can be synchronized by applying the above-mentioned measuring system and using the trigger signal.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to this embodiment and includes various modifications within a range not deviating from the gist of the present invention. Is done.

10, 20, 30, 40 Measuring system 50 Hand pump 51 Pressure calibrator 52 Pressure transmitter 60 Air conditioner 61 Air volume measuring nozzle 62 First measuring instrument 63 Second measuring instrument 100, 200, 300, 400 Control device 110, 210, 410 Pressure control device 120, 220, 310, 420 Reference device 121, 221 First inspected device 122, 222 Second inspected device 130, 230, 430 Atmospheric pressure gauge 140 Pressure measuring device 141, 341 Pressure detector 142, 342 Control Unit 143, 343 Storage unit 144, 344 Communication unit 145, 345 Display unit 146, 346 Input unit 311 and 421 Inspected device 347 Trigger control unit 348 Internal trigger generation unit 349 Trigger input switching unit 351 First input unit 352 Second input Part 353 Output part

Claims (5)

A pressure control device that controls the pressure of the fluid supplied to the pressure pipe and outputs a trigger signal that specifies the timing of measurement.
A plurality of pressure measuring devices to which the pressure pipes are connected and capable of measuring the pressure of the fluid supplied to the pressure pipes,
An atmospheric pressure gauge that measures atmospheric pressure, and
With
The plurality of pressure measuring devices and the atmospheric pressure gauge measure the pressure at the timing specified by the trigger signal, and the pressure is measured.
The plurality of pressure measuring devices calculate the measured pressure by using the atmospheric pressure measured by the atmospheric pressure gauge as a reference pressure.
By comparing the pressure calculation results of the plurality of pressure measuring devices, the plurality of pressure measuring devices are inspected or calibrated.
Measurement system. The measurement system according to claim 1, wherein the trigger signal specifies a timing for starting a series of operations for measuring pressure at a predetermined sampling cycle. It said trigger signal specifies Teisu Ru timing measuring the pressure measurement system of claim 1. The measuring system according to any one of claims 1 to 3, wherein the plurality of pressure measuring devices and the atmospheric pressure gauge are connected in a daisy chain. A pressure control device that controls the pressure of the fluid supplied to the pressure pipe and outputs a trigger signal that specifies the timing of measurement is connected to the pressure pipe, and the pressure of the fluid supplied to the pressure pipe is measured. A measurement method performed by a measurement system comprising a plurality of possible pressure measuring devices and an atmospheric pressure gauge for measuring atmospheric pressure.
The step in which the pressure control device outputs the trigger signal, and
A step in which the plurality of pressure measuring devices and the atmospheric pressure gauge receive the trigger signal, and
A step in which the plurality of pressure measuring devices and the atmospheric pressure gauge measure pressure at a timing specified by the trigger signal.
A step of calculating the measured pressure by using the atmospheric pressure measured by the atmospheric pressure gauge as a reference pressure by the plurality of pressure measuring devices.
A step of inspecting or calibrating the plurality of pressure measuring devices by comparing the pressure calculation results of the plurality of pressure measuring devices, and
Measurement methods, including.

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