JPS59170726A - Testing device for air flow meter - Google Patents

Abstract

PURPOSE:To take a speedy, accurate test through easy operation with simple constitution by comparing output signals of an air flow rate to be tested for respective flow rates set by opening and closing a sound velocity nozzle with the reference values,and deciding on and displaying whether the tested air flow meter is acceptable or not. CONSTITUTION:A cramp button 61 is pressed while a piston is held elevated to fix the body 30 to be tested at a specific position, and an electric output terminal part 31 is connected to a lead wire from a console panel 60. Then when a check start button 63 is pressed, SV meters 241-24n in an SV meter unit 20 are opened and closed according to a specific incorporated sequence to select four kinds of reference flow rate of N01-N04 successively. The measured values of the body 30 for the respective reference flow rates are compared by the airthmetic device in the console panel 60.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a test device for a gas flow meter, and more particularly, to a test device for testing the characteristics of a gas flow meter that outputs an electrical signal corresponding to an air flow rate. Settings are made by opening and closing the sonic nozzle (Sv meter), the output signal of the gas flowmeter under test 1 for each reference flow rate is compared with the reference value, and the result of the comparison is used to determine whether the gas flowmeter under test passes or fails. This is what I did.

FIG. 1 is a configuration diagram for explaining one embodiment of a test apparatus according to the present invention, in which 1o is a vacuum pump, 20 is an S
Meter unit, 3o is a gas flow meter which is the test object, 4
0 is a filter, 5o is a piston cylinder, 60 is a control device and operation panel, and when the test object 30 is set at the position shown in the figure and the vacuum pump 10 is driven, the outside air is filtered through the filter 40, the gas flow meter 30, and the S meter. It flows through unit 2o towards vacuum pump 10. On the surface of the control device and operation panel 60, there are clamps 61 and unclamp buttons 62.
, an inspection start button 63, an inspection tube head button 64, etc., and each flow rate (in the illustrated example, the number 4 from Muma NOI to No. 4)
When the clamp button 61 is pressed, the piston of the piston cylinder 50 moves downward and moves to the right in the piston car H of the other piston cylinder 70, and is unclamped. When the button 62 is pressed, the screw I-h'1 of the piston cylinder 50 moves toward the left side, and the piston of the piston cylinder 70 returns to the left. Now, with the screw 1 raised to one side, place the test object 30 in the position shown and press the clamp button 6], and the screw 1 of the screw 1 cylinder 50 will move downward. to fix the V test specimen 30 in a predetermined position, and screw F3 and screw 1 to the cylinder 7.
When the piston 0 is moved to the right (connect the electrical output terminal section 31 of the test object 30 to the wire from the operation panel 60) and press the test start button 63, the SV meter unit will start. The S meters 24□ to 24n in 1-20 are opened and closed according to a predetermined sequence built in in advance. 13 flow rates are sequentially selected, and the test object 3oOit mq value for each reference flow rate is compared by the arithmetic unit in the operation panel 60.

That is, inside the SV meter unit l-20, the partition wall 21
The partition wall 21 is provided with SV meters 24□ to 24n that selectively communicate the front chamber 22 and the rear chamber 23. ．． 24n is opened and closed by the piston cylinder 25 according to a sequence built into the control section of the operation panel 60
□~25r1 are selectively opened and closed to create a reference flow rate for the test object 3o. Figure 2 shows the characteristic curve of the test object 3o.
The horizontal axis shows the flow rate, the vertical axis shows the output voltage, the curve @ is the standard characteristic curve, ■ is the tolerance 1 limit curve, (■ is the tolerance lower limit curve, Ql
-O4 is the test flow rate, each test flow rate corresponds to the display lamp Noz to NΩ4 on the operation panel 60, and each test flow rate Q
The reference values E1 to E4 for □ to Q4 are stored in advance in the memory within the operation panel 6o. At this point, when you return to the original state and press the above-mentioned test start button 63, the SV meter 24. −
24n is opened and closed according to a sequence preset in the operation panel 60, Q and 1 are sequentially created to the reference flow rate Q1, and the output signal of the test object 30 tilted to each meteor Q□ to Q4 is operated. It is compared with the reference value (curve ■) stored in advance in the memory in the board 60, and each comparison result is calculated between the upper limit [wa and cho limit ◎a'I - curve (within the shaded range) ) is N.

It is displayed in the GO display month of 1 to No. 4, and when it is outside the allowable range, it is displayed on the NG indicator light. In addition, it is necessary to maintain the pressure before and after the SV meter within a critical pressure. Therefore, it is necessary to maintain the upstream pressure, temperature, and humidity constant at 1°, or to keep these constant. Since it is difficult to maintain the pressure, temperature, humidity, etc. in the SV meter unit, these detection signals are guided to the control device and the calculation section in the operation panel 60. , here, a predetermined correction is added (the first
In the figure, these detectors are omitted), and
Generally, natural numbers are selected as the reference values 1 to Q4, but the rated flow rate of each SV meter is not necessarily based on natural numbers, and the reference flow rate is created by combining several S meters. Therefore, the actual reference flow rate determined by the S meter selection is Q1 to Q4 shown in the diagram.
It does not necessarily match the actual flow value, and there may be some discrepancies, so in that case, add corrections to the reference value according to 11. T gas pressure, temperature, humidity, etc. to correspond to the actual wind flow value. The converted value is then converted back to the reference value, and this converted value is compared with the detection signal from the test object.

As is clear from the following explanation, according to the present invention, the gas flow rate can be tested quickly and accurately with a simple configuration and operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a gas flow meter testing device according to the present invention, and FIG. 2 is a diagram showing an example of a reference characteristic curve used in implementing the present invention. 10 Vacuum pump, 20・S Xr□meter unit 1
-1241= 24 n -S V meter, 30 - Test object, 40 - Filter, 50 Screw 1 cylinder, 60 - Control device and operation panel, 70 Screw 1 cylinder.

Claims (1)

[Claims] A large number of sonic nozzle groups arranged in parallel in a fluid path, a control device that selectively controls opening and closing of each sonic nozzle, and a gas flowmeter under test formed in series with the sonic nozzle group in the fluid path. an outside air introduction filter formed on the upstream side of the test gas flowmeter arrangement section, and a negative pressure source arranged on the downstream side of the sonic nozzle group; In a test device for a gas flow meter, the gas flow meter under test is disposed in a gas flow meter installation portion, and the sonic nozzle is selectively controlled to open and close to test the gas flow meter under test. A reference value for each flow rate is stored in a memory in advance, and the output signal of the gas flowmeter under test for each flow rate is compared with the reference value, and the result of the comparison is used to determine and display whether the gas flowmeter under test passes or fails. A testing device for a gas flowmeter, characterized in that: