JPH11148881A - Calibration apparatus for pressure converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a calibration apparatus, for a pressure converter, by which a static pressure can be calibrated simultaneously regarding a plurality of pressure converters while a pressure is set over a wide range and by which a dynamic characteristic with reference to shock waves can be calibrated. SOLUTION: The inside of a tube body B is partitioned, by two diaphragms 6, into a low-pressure chamber 3, a double-diaphragm chamber 4 and a high- pressure chamber 5. In the low-pressure chamber 3, a mounting part for a plurality of pressure converters 2 to be calibrated is installed in a tube end part, and a mounting part for a plurality of pressure converters used to measure the speed of shock waves is installed in a tube trunk part in positions (a) to (e) by keeping an interval. Pressure converters 15-1 to 15-3, for pressure setting, which set a pressure in every chamber and gas supply sources 7, 8, via pressure regulating valves 14-1, 14-2, in order to be pressurized to a prescribed internal pressure are connected respectively to the low-pressure chamber 3, the double- diaphragm chamber 4 and the high-pressure chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure transducer calibration apparatus for performing static pressure calibration of a pressure transducer (pressure sensor) and dynamic pressure calibration by a shock wave.

[0002]

2. Description of the Related Art Pressure transducers are widely used in wind tunnel tests and the like. In use, pressure transducers are used together with static pressure calibration, and when measuring shock wave propagation velocity, their dynamic characteristics are measured and calibrated. It is necessary to determine the relationship between the set pressure and the output signal for the pressure transducer.

[0003] Static / dynamic pressure calibration devices for calibrating pressure transducers have already been developed in Japan and abroad. However, each device has a configuration for calibrating a single pressure transducer, and a plurality of pressure transducers are provided. No pressure transducer has been proposed that can simultaneously and statically and dynamically calibrate the pressure.

Here, a conventional pressure transducer calibrating device will be specifically described. First, as a static characteristic calibration device,
A weight calibration device that uses gas (air) and a weight to generate the pressure required for the calibration, and a piston calibration that generates pressure by compressing with a screw or piston using gas (air) and liquid (oil). There is a device.

[0005] Next, as a dynamic characteristic calibration device, an impulse-type pressure calibration that generates a dynamic pressure by holding a weight in a vertical cylinder, adjusting the height of the weight as appropriate, and instantaneously dropping the weight. There is a device. Each of these conventional pressure transducer calibration devices is a device for calibrating one pressure transducer.

FIG. 3 shows an example of a pressure setting system in a weight type static pressure calibration device as one of the conventional calibration devices. In FIG. 3, 21 is a pressure supply source, 22 is a filter, 23 is an intake valve, 24 is a flow meter, and 25-
1, 25-2 are tanks, 26 is a weight, 27 is a pressure setting unit, 28 is a pressure extraction valve, and 30 is a steel ball for balancing.

[0007] Pressurized air from the pressure supply source 21 is supplied to the tank 25-1 via the filter 22, the pressure inlet valve 23, and the flow meter 24. The compressed air from the tank 25-1 is guided to the pressure setting unit 27, and is set to a pressure balanced with the weight of the weight 26, and the air having the set pressure is supplied from the pressure setting unit 27 to the tank 25-2 and the pressure extraction valve. 28
Via the adapter to the single pressure transducer to be calibrated, which is connected via an adapter to A, and the static characteristics at that pressure are calibrated. 29 is a bypass valve.

[0008] The pressure extraction valve 28 is used to open and close the flow path when the weight 26 is increased or decreased. Weight-type static pressure calibration devices using this pressure setting system are limited to the calibration of a single pressure transducer due to the pressure capability.

[0009]

As described above,
The conventional pressure transducer calibrator can only calibrate a single pressure transducer and cannot calibrate a plurality of pressure transducers at the same time. Further, since the pressure range differs depending on the calibration device, calibration in a wide range from low pressure to medium pressure and high pressure cannot be performed by one calibration device.

Further, in the conventional calibration apparatus, there has not been provided any apparatus having a function of generating a shock wave at high pressure and high speed and capable of dynamically calibrating a pressure transducer for a shock wave.

An object of the present invention is to provide a pressure transducer calibrating apparatus capable of simultaneously calibrating a plurality of pressure transducers under a wide range of pressure settings. Still another object of the present invention is to provide a pressure transducer calibrating apparatus that can simultaneously calibrate dynamic characteristics of a plurality of pressure transducers against a shock wave under a set high pressure in addition to the above. .

[0012]

According to the present invention, there is provided a pressure transducer calibrating device for solving the above-mentioned problems, comprising a diaphragm for generating a shock wave due to breakage and a low pressure chamber inside a tube.
The chamber is divided into a double diaphragm chamber and a high-pressure chamber. In the low-pressure chamber, a plurality of pressure transducers to be calibrated are attached at the end of the pipe, and the shock wave velocity is measured in the pipe body at intervals in the pipe axis direction. And a configuration in which a plurality of pressure transducers are attached.

Each of the low-pressure chamber, the double-diaphragm chamber and the high-pressure chamber is supplied with a gas through a pressure setting pressure transducer for setting the pressure in each chamber and a pressure regulating valve for pressurizing the inside to a required pressure. Connect the source. The pressure setting may be manual or automatic.

The pressure transducer calibrating apparatus according to the present invention has the above-described structure, and a plurality of pressure transducers to be calibrated are mounted on a mounting portion at a pipe end of the low pressure chamber, and a predetermined pressure is applied to the low pressure chamber. And the static pressure calibration can be performed for the plurality of pressure transducers to be calibrated.

For this purpose, first, the pressure regulating valve is adjusted to supply gas from a gas supply source and pressurize the gas. The pressure transducer for setting the pressure in the low-pressure chamber detects and feeds back the pressure in the low-pressure chamber, and sets the low-pressure chamber to a desired pressure. In this manner, a plurality of pressure transducers to be calibrated attached to the pipe end can be calibrated at the same time by setting the low-pressure chamber to a predetermined pressure.

Next, the calibration of the dynamic characteristics of the plurality of pressure transducers to be calibrated attached to the pipe end of the low-pressure chamber by the shock wave is performed as follows. Can be performed simultaneously on the vessel.

First, a plurality of pressure transducers for measuring shock waves are mounted on the mounting portion of the tube body. Then, each pressure regulating valve is set so that the pressure in the low pressure chamber, the double diaphragm chamber, and the high pressure chamber becomes a predetermined value, and air is introduced into each chamber from a gas supply source to bring each chamber to a set pressure.

From this state, the pressure in the double diaphragm chamber and the high-pressure chamber is further increased to a level just before the diaphragm is broken.
Reduce the pressure in the double diaphragm chamber. As a result, the pressure difference between the double diaphragm chamber and the high-pressure chamber gradually increases, and finally the diaphragm partitioning the inside of the tube is broken, and a shock wave is generated.

The speed of the shock wave generated by the instantaneous breakage of the diaphragm was measured from the outputs of a plurality of pressure transducers mounted on the pipe body of the low-pressure chamber, and was mounted on the pipe end of the low-pressure chamber. Data on dynamic characteristics due to shock waves in a plurality of pressure transducers to be calibrated are measured.

As described above, according to the present invention, a pressure converter capable of simultaneously performing static pressure calibration for a plurality of pressure transducers under a wide range of pressure settings and dynamic pressure calibration for shock waves. An instrument calibration device is provided.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressure transducer calibrating apparatus according to the present invention will be described in detail with reference to one embodiment shown in FIGS. In FIG. 1, B is a cylindrical body constituting a small shock tube of the pressure transducer calibration device, and 1 is a tube end disk (flange). The tube end disk 1 is provided with a mounting portion for mounting a plurality of pressure transducers 2 to be calibrated.

The tubular body B is divided into three sections, a low-pressure chamber 3, a double-diaphragm chamber 4, and a high-pressure chamber 5, by two diaphragms 6 in the axial direction of the tube. The diaphragm 6 has a cross-shaped groove in the center, and the groove is broken at a set pressure by changing the depth, width, and length. 7 and 8 are gas sources.

Reference numerals 9-1 to 9-5 denote solenoid valves.
10-4 is a needle valve, and 11-1 to 11-8 are ball valves. Numeral 12 denotes a pump connected to each of the chambers 3 to 5 so as to be able to evacuate, and numeral 13 denotes a filter. 14-
Reference numerals 1 and 14-2 denote pressure regulating valves, and 15-1 to 15-3 denote pressure setting pressure transducers attached to the respective chambers.

Also, a, b, c,
At the locations indicated by d and e, mounting portions for pressure transducers for measuring the shock wave velocity are provided.

Next, FIG. 2 shows a pressure control system of the calibration device shown in FIG.
Reference numeral 17 denotes a servo amplifier, and 18 denotes a computer operation unit.

The low-pressure chamber 3, the double-diaphragm chamber 4, and the high-pressure chamber 5 are respectively provided with pressure regulating valves 14-1, 14-2, a filter 13,
Needle valves 10-1, 10-2, 10-3, solenoid valve 9-
The gas supply source is communicated via 1, 9-2, 9-3.

On the other hand, the low pressure chamber 3 is a solenoid valve 9-4, the double diaphragm chamber 4 is a ball valve 11-4, and the high pressure chamber 5 is a ball valve 11-5.
After passing through each of the pumps 1 through the ball valve 11-7.
2 has been contacted.

The plurality of pressure transducers 2 to be calibrated attached to the tube end disk 1 of the low pressure chamber 3 by the pressure transducer calibrating apparatus shown in FIG. Calibration and dynamic pressure calibration by shock waves can be performed as follows.

(1) Static pressure calibration: A plurality of pressure transducers 2 to be calibrated are attached to a tube end disk (flange) 1 constituting a small shock tube (circular tube body) B, and each pressure transducer 2 is calibrated. The input / output cable of the pressure transducer 2 for calibration is connected to a measuring device (not shown), and preparation is made so that the electric signal output of each pressure transducer for calibration can be measured.

The cylindrical body B constituting the small shock tube has a diaphragm 6
To partition the low pressure chamber 3 and the double diaphragm chamber 4 from each other.
The pressure is sealed in the pressure supply source 7 (eg, a nitrogen cylinder), and the pressure regulating valve 14-1 is adjusted to a predetermined pressure.

Open the ball valve 11-1 (at this time, 11-
2 is closed), and waits for an open / close command for the solenoid valve 9-1. The needle valve 10 is normally open during the calibration test. Solenoid valve 9-4
Is normally closed during the calibration test.

A command is given to the servo amplifier 17 of the measuring device by a signal from the set pressure command section 16 of the computer, and the solenoid valve 9-1 starts opening operation by the signal. Solenoid valve 9
Simultaneously with the opening of -1, the pressure from the pressure supply source 7 is filled with gas in the low pressure chamber 3 of the circular tube body B constituting the small shock wave tube, and the low pressure chamber 3 rises to a pressure corresponding to the command signal.

The pressure in the low-pressure chamber 3 is sensed by the pressure setting pressure transducer 15-1, this output signal is fed back and calculated by the calculator 18 and then compared by the comparator. 17 to operate the solenoid valve 9-1.

As a result of this repetition, when the deviation becomes close to zero (the deviation width is predetermined), the pressure in the low-pressure chamber 3 of the circular tube body B constituting the small shock tube becomes a predetermined pressure.
At that time, the measurement of the pressure transducer for calibration 2 is started.

This operation is repeated several times, and the correspondence between the output from the plurality of pressure transducers 2 to be calibrated to several set pressures is determined. As described above, static pressure calibration is simultaneously performed on the pressure transducer 2 to be calibrated.

(2) Shock Wave Generation and Dynamic Pressure Calibration by Shock Wave: When performing dynamic pressure calibration by a shock wave, a plurality of pressure transducers 2 to be calibrated to the tube end disk (flange) 1 A pressure transducer for measuring a shock wave velocity is mounted on a mounting portion (portion a to e in FIG. 1) which is mounted in the same manner as in 1) and is spaced apart from the tube body of the low-pressure chamber 3.

The ball valves 11-2 and 11-3 are closed, and the pressure adjusting valves 14-1 and 14-2 are set to required pressures, and are kept in the same state. Needle valves 10-1, 10-2, 10
-3 are all open. The solenoid valves 9-1, 9-2, and 9-3 are in a command standby state from the computer and are fully closed. Solenoid valve 9
-4, open the needle valves 11-4 and 11-5. At this time, the solenoid valve 9-5 and the ball valves 11-7 and 11-8 are closed,
The ball valve 11-6 is opened for pressure monitoring.

In this state, the ball valve 11-7 is opened and the pump 12 is started to facilitate setting of the pressure in the tubular body B. In a state where the inside of the tubular body B is in a vacuum state,
Is stopped, and the ball valve 11-7 is closed. From this vacuum state, the solenoid valves 9-1, 9-2, and 9-3 are gradually opened according to a computer command so that the pressures in the low-pressure chamber 3, the double diaphragm chamber 4, and the high-pressure chamber 5 become constant. The pressure in the tubular body B is set to a required pressure.

In order to damage the diaphragm 6, the solenoid valve 9-1 is closed in this state, and the solenoid valves 9-2 and 9-3 are further opened according to a command from the set pressure command unit 16 of the computer. Increase to pressure. Thereafter, the solenoid valve 9-2 is further opened, and the solenoid valve 9-3 is similarly opened to increase the pressure in the double diaphragm chamber 4 and the high-pressure chamber 5.

In this state, in order to prevent the diaphragm 6 from being broken, it is checked in advance which pressure difference the diaphragm 6 will be damaged.
The pressure in the double diaphragm chamber 4 and the high pressure chamber 5 is increased to a value just before breakage.

The predetermined pressure is set between the double diaphragm chamber 4 and the high pressure chamber 5.
Is completed, the solenoid valve 9-4 and the needle valve 11-5 are closed. With only the needle valve 11-4 opened, the needle valve 11-7 is opened and the pump 12 is started. By gradually evacuating the double diaphragm chamber 4 in this manner,
A pressure difference is created between the high pressure chamber 5 and the double diaphragm chamber 4 and between the double diaphragm chamber 4 and the low pressure chamber 3.

When a certain pressure difference is reached, the diaphragm 6 is instantaneously broken, and a shock wave can be generated in the low-pressure chamber 3. By using the output of the pressure setting pressure transducer 15-1 as a trigger at the same time as the breakage of the diaphragm 6, the measurement of the pressure transducers attached to the a to e of the tube cylinder of the low-pressure chamber 3 is started, and the required data is obtained. To get.

The pressure transducers are spaced a along the tube axis.
E, the shock wave velocity with respect to the distance between the axes can be obtained by a computer, and the average velocity can be obtained by comparing the rise times of the data of the pressure transducers. After completion of the series of tests, drain needle valves are provided at various places so that the pressure in each pipe can be returned to the atmospheric state.

Thus, a shock wave can be generated in the cylindrical body B constituting the small shock wave tube, and dynamic pressure calibration of the plurality of pressure transducers to be calibrated can be simultaneously performed on the shock wave.

As described above, the present invention has been specifically described based on the illustrated embodiments. However, the present invention is not limited to these embodiments, and specific structures within the scope of the present invention shown in the claims are set forth. Needless to say, various changes may be made to the configuration.

For example, in the above embodiment, a circular tube is used as the tube B, but it is not necessarily required to be a circular tube.
The number of pressure transducers to be calibrated and the number of pressure transducers for measuring shock wave velocity may be arbitrarily selected.

[0047]

As described above, according to the present invention, the inside of the tube is divided into a low-pressure chamber, a double-diaphragm chamber and a high-pressure chamber by two diaphragms. A mounting part for a pressure transducer for calibration and a mounting part for a plurality of pressure transducers for measuring a shock wave velocity, which are mounted on a pipe body at intervals in a pipe axis direction.

Each of the low-pressure chamber, the double-diaphragm chamber and the high-pressure chamber is provided with a pressure setting pressure transducer for setting the pressure in each chamber and a pressure regulating valve for pressurizing to a required internal pressure. And a gas supply source.

According to this, it is possible to pressurize the low-pressure chamber to a predetermined pressure and simultaneously perform static pressure calibration of the plurality of pressure transducers to be calibrated attached to the pipe end.

Further, the pipe is partitioned into a low-pressure chamber, a double-diaphragm chamber, and a high-pressure chamber by a diaphragm, and a high-pressure difference is generated between the double-diaphragm chamber and the high-pressure chamber, thereby damaging the diaphragm between the two chambers and causing a shock wave. Is generated, the velocity of the shock wave is measured by a pressure transducer attached to the tube body, and dynamic pressure calibration of a plurality of pressure transducers to be calibrated by the shock wave can be performed simultaneously.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a pressure transducer calibration device according to an embodiment of the present invention.

FIG. 2 is a system diagram showing a pressure control system in the pressure transducer calibration device shown in FIG.

FIG. 3 is an explanatory diagram showing an example of a pressure setting system in a conventional weight-type static pressure calibration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube end disk (flange) 2 Pressure transducer for calibration 3 Low pressure chamber of small shock tube 4 Double diaphragm room of small shock tube 5 High pressure room of small shock tube 6 Diaphragm 7 Gas supply source (NO.1 system) 8) Gas supply source (NO.2 system) 9 Solenoid valve 10 Needle valve 11 Ball valve 12 Pump 13 Filter 14 Pressure regulating valve 15 Pressure setting pressure converter 16 Computer setting pressure command section 17 Servo amplifier 18 Computer calculation section 21 Pressure supply source 22 Filter 23 Pressure inlet valve 24 Flow meter 25 Tank 26 Weight 27 Pressure setting section 28 Pressure outlet valve 29 Bypass valve 30 Steel ball for balance

Claims (1)

[Claims] 1. The interior of a tube can be partitioned into a low-pressure chamber, a double-diaphragm chamber, and a high-pressure chamber by two diaphragms for generating a shock wave due to breakage. A mounting portion for a pressure transducer for calibration and a mounting portion for a plurality of pressure transducers for measuring a shock wave velocity, which are mounted on the pipe body at intervals in the pipe axis direction, are provided. Each of the double diaphragm chamber and the high pressure chamber is connected to a pressure setting pressure transducer for setting the pressure in each chamber and a gas supply source via a pressure regulating valve to pressurize to a required internal pressure. A pressure transducer calibration device, comprising: