CN2035882U

CN2035882U - Correcting device for pressure gauge

Info

Publication number: CN2035882U
Application number: CN 88213317
Authority: CN
Inventors: 李庆华; 李建国
Original assignee: NO 38610 TROOP SURVEYING TECHN
Current assignee: NO 38610 TROOP SURVEYING TECHN
Priority date: 1988-09-16
Filing date: 1988-09-16
Publication date: 1989-04-12

Abstract

The utility model provides a calibration device for a pressure gauge. The calibration device for a pressure gauge is suitable for the precise measurement and correction for a pressure gauge. A calibrated instrument and a pressure sensor are arranged on the same air passage device; the non-electrical pressure signal of the air pressure in the air passage is converted to an analogy voltage signal through the pressure sensor, the analogy voltage signal is converted to a frequency signal through a voltage-frequency converter, the frequency signal is processed through a microcomputer, and the accurate value of the air pressure in the air passage can be obtained; the error of the calibrated instrument can be found out through the accurate value, and the calibrated instrument is corrected through the error value. The utility model has the advantages of convenient operation, high precision, and low cost; the working for loading and unloading weights is omitted.

Description

Correcting device for pressure gauge

The utility model relates to a kind of manometer calibration device, is applicable to barometric delicate metering and correction.

In order to guarantee barometric precision, tensimeter all needs to calibrate in use for some time.Pressure correction method commonly used now is: will be placed on the gas circuit tester by the tensimeter in school, utilize the trim counterweight to measure the error of calibrated meter, then calibrated meter is revised, this method exist parallax big, move to join and press counterweight labour intensity height, speed waits problem slowly.

In order to overcome the problem of above-mentioned existence, the purpose of this utility model is to propose a kind of pressure measurement calibration measurement device by piezoresistive transducer.

The purpose of this utility model is achieved in that calibrated meter and pressure transducer are loaded on the same gas path device, Pneumatic pipe cleaner excess pressure sensor in the gas circuit converts the pressure signal of its non electrical quantity to the voltage signal of simulation, convert the voltage signal of simulation to frequency signal through voltage one frequency converter, utilize microprocessor to handle to its frequency signal, can obtain the exact value of gas circuit internal gas pressure, utilize this value can find out the error of calibrated meter, calibrated meter is revised according to its error amount.

The utility model has the advantages that the manometer calibration device is easy and simple to handle, measure accurately that saved the heavy work of loading and unloading heavy counterweight, cost is low.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof

Fig. 1 manometer calibration device calcspar

Fig. 2 manometer calibration device gas circuit synoptic diagram

Fig. 3 manometer calibration device operational amplifier and voltage one freq converting circuit synoptic diagram

Fig. 4 manometer calibration device data acquisition processing system calcspar

Fig. 5 manometer calibration device logic control schematic diagram

Manometer calibration device (see figure 1) of the present utility model is made up of gas circuit 1, calibrated meter 2, pressure transducer 3, linear expansion circuit 4, voltage one freq converting circuit 5, data acquisition processing system 6 and stabilized voltage supply 7 etc.Of the present utility model being characterised in that utilizes linear expansion circuit 4 to make the linear working range of pressure transducer 3 be expanded, utilize voltage one freq converting circuit 5 to convert pressure signal to frequency signal, then this frequency signal is shown or record after data acquisition processing system 6 is handled.The constructional device of gas circuit 1 is seen Fig. 2, and it includes equalizer valve 8, gas circuit fine setting and impact damper 9, air chamber 10, air chamber 11, calibrated meter interface 12, pressure sensor interface 13 and reduction valve 14.Equalizer valve 8 and reduction valve 14 are controlled by K switch 1, K2, and both select solenoid valve for use.The gas circuit structure part is by the metal processing and fabricating, and pressure transducer 3 is selected the diffuse si sensor of good linearity for use.Linear expansion circuit 4 and voltage one freq converting circuit 5 are selected operational amplifier module XFC and voltage one frequency translation module VFC for use, and its circuit working principle is seen Fig. 3.Resistive element R1, R2, R3, R4, the R5 of operational amplifier and voltage one freq converting circuit 5 select the resistance about 10K, 120K, 18K, 18K and 120K ohm respectively for use in the present embodiment, and R6, R7, R8 select the adjustable resistance of 2.7K, 500,50K respectively for use.C1, C2 are electric capacity, and C1, C2 select for use respectively about 5.1PF, 1000PF.

The calcspar of data acquisition processing system 6 is seen Fig. 4, and it includes microprocessor 15, counter J1 and J2, buffer T1 and T2, counter controls gate Q, CRT monitor 16, logic control circuit 18 and printer LP.The microprocessor 15 of present embodiment is selected PC-8300 or PC-81 for use, because the C4005 function among the PC-8300 is limited, can not be used to manage the logical operation of counter J1 and J2, buffer T1 and T2 etc., for this reason, increased Combinational Logic Control circuit 18 in the data acquisition processing system 6, to cooperate the logical operation of CPU, C4005 realization to counter J1 and J2 and buffer T1 and T2.Figure 5 shows that manometer calibration device logic control schematic diagram, it includes counter J1 and J2, buffer T1 and T2, counter controls gate Q, CRT monitor 16, printer LP and logic control circuit 18, and logic control circuit 18 is by AND circuit A1, A2, A3, A4; OR circuit H1, H2, H3, H4, H5, H6, H7; Not circuit N1, N2, N3, N4 form.Y among Fig. 5, B all represent the data line of each logic element and microprocessor 15.Counter J1 and J2 select for use two eight-digit binary number counter J1 and J2 serial to use, in order to the numerical ability of extension counter.The numerical ability of this counter surpasses more than 65500, compares with the sixteen bit A/D event counter with the capacity numerical ability, and cost reduces greatly.The counter that utilizes this serial to use, its counting precision reach 6.5 ten thousand/.The high one of the main reasons of this manometer calibration device precision of the present utility model just.Counter J1 and J2 counting beginning and ending time are subjected to the control of counter controls gate Q, and counter controls gate Q present embodiment is selected monostable trigger for use.Data acquisition program is recorded on magnetic tape station 17, during use program is read in microprocessor 15 from magnetic tape station 17.

The course of work of manometer calibration device of the present utility model is described below:

Open equalizer valve 8, be charged to certain pressure in the gas circuit 1.This moment, air chamber 10 was identical with the force value of air chamber 11.After the gas circuit 1 interior pressurising, pressure transducer 3 produces one and its pressure corresponding voltage signal output under the effect of gas circuit 1 internal pressure, in the efficient working range of pressure transducer 3, air pressure in the size of voltage output signal and the gas circuit 1 becomes approximate linear, this signal amplifies and to its non-linear compensating through linear expanded circuit 4, make the range of linearity of voltage signal further expand, improved the working range of pressure transducer 3.The output voltage signal of linear expansion circuit 4 adds to voltage one freq converting circuit 5, and the output frequency signal CP of voltage one freq converting circuit 5 is directly proportional with its input voltage.So, the output frequency signal CP of voltage-frequency converting circuit 5 has reflected the size of gas circuit 1 internal gas pressure.Voltage-frequency converting circuit 5 output frequency signal CP can obtain the accurate force value in the gas circuit 1 after data acquisition processing system 6 is handled, utilize CRT monitor 16 demonstrations or printer LP to carry out record.Can be in practical operation by regulating the gas circuit fine setting and impact damper 9 in the gas circuit 1, gaseous tension in the gas circuit 1 is transferred to a rational numerical (as some integer force value), check displayed value poor of the pressure indicated value of calibrated meter 2 and CRT monitor 16 then, this difference is considered to the error of calibrated meter 2, and error can be revised calibrated meter 2 in view of the above.

When manometer calibration device data acquisition processing system 6 of the present utility model is worked the program on the magnetic tape station 17 is read in microprocessor 15, microprocessor 15 passes through data line Y1 with program, B2, B3, B4, B5 and B1, Y2, Y3 is through A1, N1, H1, N2, A2, N3 adds to code translator P, make code translator P work, microprocessor 15 programs are through Y4, Y5 input code translator P, the signal that code translator P produces adds to H2 and generates reset signal, clear counter J1 and J2, the signal that produces H3 then adds to counter controls gate Q, the output signal of counter controls gate Q and add to counter J1 and J2 through A4 together from the output frequency signal CP of voltage one freq converting circuit 5 makes counter J1 and J2 gather data from output frequency signal CP.Microprocessor 15 also by data line Y6 to or door H2, H3, H4, H5 control.Also export a signal at counter controls gate Q in the A4 output signal and add to H6, H6 also receives the signal from printer LP simultaneously.The output of H6 adds to not circuit N4, the output of not circuit N4 adds to A3 with the signal from the data line Y7 of microprocessor 15, the data line Y8 that exports to of A3 imports microprocessor 15, and its effect is that microprocessor 15 is hung up.When counter controls gate Q service time finishes, wake microprocessor 15 up through H6, N4, A3 again, from buffer T1 and T2 peek.At this moment microprocessor 15 sends signal through data line Y4, Y5 and opens buffer T1 and T2 through code translator P to H4, H5, buffer T1 and T2 serve bus input microprocessor 15 with the data of counter J1 and J2 collection respectively, and this moment, code translator P still was subjected to the combinational logic signal controlling that A1, N1, H1 and N2, A2, N3 produce.After peek is finished, all hung up by the various piece of Combinational Logic Control.

When if program requires printout, still make code translator P work through combinational logic.The signal that this moment, Y4, Y5 produced through code translator P and add to H7 together from the signal of Y9, the output of H7 adds to printer LP, printer LP can obtain data from bus and printed this moment, printer LP enters busy attitude, and the signal that also produces through H6, N4 of the attitude signal that will hurry and add to A3 together from the signal of Y7, the output notice microprocessor 15 of A3 is finished up to printing, sends into the data of next time gathering by microprocessor 15 again, otherwise finishes to print.

Pressure transducer 3 of the present utility model, gas circuit 1 etc. can be configured according to the requirement of working pressure, can accomplish series digit formula pressure measurement calibrating installations such as 0-1 MPa, 0.1-10 MPa, 1-100 MPa.

Correcting device for pressure gauge of the present utility model is the digital pressure measurement calibrating installation of intelligent frequency, comes metering pressure can accomplish 0.00001 MPa with frequency counting, and measuring accuracy is had great potentialities and can be dug, and can only accomplish 0.005 MPa with the counterweight minimum. Except can using standard atmospheric pressure " MPa " metering, also available kg/cm, millimetres of mercury and the millimeter of water etc. are carried out pressure measurement.

The nonlinear precision of solid state resistance pressure sensor is generally about 0.1%, do not reach the measuring accuracy of requirement, for addressing this problem, improve linear relationship and pressure measurement precision that the pressure non electrical quantity changes electric weight into, carry out the change in resistance rule theoretical calculate of pressure and piezoresistance sensor, and carried out the test checking computations. On this theoretical foundation, improved the linearity of piezoresistance sensor, its precision is reached more than 0.999999.

Claims

1, a kind of manometer calibration device, form by gas circuit 1 and calibrated meter 2, pressure sensor interface 13 places that are characterised in that of the present utility model add a pressure transducer 3 that pressure signal is converted to electric signal, linear expansion circuit 4, convert the voltage signal of pressure transducer 3 output to the voltage-frequency converting circuit 5 of frequency signal, the data acquisition processing system 6 and the stabilized voltage supply 7 of the output frequency of voltage-frequency converting circuit 5 being carried out data acquisition and processing (DAP).

2, manometer calibration device according to claim 1 is characterized in that above-mentioned pressure transducer 3 selects the diffuse si piezoresistance sensor for use.

3, manometer calibration device according to claim 1, it is characterized in that above-mentioned linear expansion circuit 4 and voltage one freq converting circuit 5 select for use by operational amplifier module and voltage one freq converting circuit module and resistance R 1, R2, R3, R4, R5, R6, R7, R8, the circuit that capacitor C 1, C2 form.

4, manometer calibration device according to claim 1 is characterized in that above-mentioned data acquisition processing system 6 is made up of microprocessor 15, counter J1 and J2, buffer T1 and T2, counter controls gate Q, CRT monitor 16, logic control circuit 18 and printer LP.

5, manometer calibration device according to claim 1 or 5, it is characterized in that above-mentioned data acquisition processing system 6 includes is used to cooperate CPU, C4005 to realize that the logic control circuit 18 to counter J1 and J2, buffer T1 and T2 is by AND circuit A1, A2, A3, A4, OR circuit H1, H2, H3, H4, H5, H6, H7, not circuit N1, N2, N3, N4 form.