CN101865748A - Normalization compensation method of diffusion silicon pressure sensor - Google Patents

Abstract

The invention discloses a normalization compensation method of a diffusion silicon pressure sensor, belonging to the pressure automatic test and control system field and comprising a bridge-shaped circuit of the diffusion silicon sensor. The invention is characterized in that a current input end or a voltage input end of the bridge-shaped circuit is connected with a first resistance R1 in series, and then a second resistance R2 is connected with the first resistance R1 and the bridge-shaped circuit in parallel. In the method of the invention, a full range magnitude regulation circuit is added in the original circuit in which full range temperature compensation is carried out on the pressure sensor and a sophisticated compensation calculation method is formed. On the basis of non-affecting other properties of the sensor, outputs of all sensors are compensated according to a constant value which can be regulated at random according to the requirement of a client.

Description

The normalization compensation method of diffusion silicon pressure sensor

Technical field

The invention belongs to pressure automatic test, control system field, be specifically related to a kind of normalization compensation method of diffusion silicon pressure sensor.

Background technology

Diffusion silicon pressure sensor belongs to the responsive industry in intelligent measure fields such as pressure, temperature, flow, is the basic device in the pressure survey.For a long time, it is the bottleneck that the restraining pressure instrument is produced that pressure sensor signal is handled, and the scope of pressure transducer output is full of forgiveness, from several millivolts to hundreds of millivolts, causes complicated, the trouble of follow-up instrument conditioning.Everybody wishes that sensor uses as a normal component, solidifies output, can simplify like this and the follow-up modulate circuit of standardization, enhances productivity greatly.

Summary of the invention

The present invention was originally carrying out in the full scale temperature compensation circuit pressure transducer, had added full scale size adjustment circuit again, and had formed ripe compensation computing method.On the basis that does not influence other performances of sensor, the output of all the sensors is compensated according to a definite value.This value can be according to customer requirement and regulated at will.

The concrete scheme that the present invention adopts is:

A kind of normalization compensation method of diffusion silicon pressure sensor, comprise diffuse si sensor bridge type circuit, it is characterized in that be connected in series first resistance R 1 at bridge type circuital current input end or voltage input end earlier, it is in parallel with first resistance R 1 and bridge type circuit that second resistance R 2 is set then.

Beneficial effect of the present invention is: originally pressure transducer was being carried out in the full scale temperature compensation circuit, and adding full scale size adjustment circuit again, and forming ripe computing method.On the basis that does not influence other performances of sensor, the output of all the sensors is compensated according to a definite value.This value can be according to customer requirement and regulated at will.Through the reality test, the full scale temperature characterisitic is adjusted effect and was not changed in the past, and the normalization output accuracy can reach ± 1%FS.

Description of drawings

Fig. 1 is the diffusion silicon pressure sensor schematic diagram;

Fig. 2 is a constant current source diffusion silicon pressure sensor schematic diagram of the present invention;

Fig. 3 is a constant pressure source diffusion silicon pressure sensor schematic diagram of the present invention.

Embodiment

As shown in Figure 1, definition:

Full scale output: Sc=V1c-V0c Sh=V1h-V0h

Sensor internal resistance: Rc=Ec/I Rh=Eh/I

Wherein, S: full scale output; R: sensor input impedance; V: sensor output voltage; E: sensor input voltage; Full pressure; 0: zero pressure; C: low temperature; H: high temperature; N: normal temperature.

R1, R2 have constituted diffusion silicon pressure sensor full scale temperature adjustment circuit and full scale output regulation circuit among the figure as shown in Figure 2, ifq circuit (only can adjust the full scale temperature characterisitic) has only R2, and do not have R1, and having under R1 and the R2 condition, require: 1, Sc=Sh; 2, (100mV of this place is exactly normalized designated value to Sc=Sh=100mV, also can specify other values.)

Because sensor output and sensor power supply (constant current source power supply) are directly proportional, so condition 1 can be written as

And:

So:

Put in order:

Under the normal temperature (n represents normal temperature), Sn=V1n-V0n, so the condition 2 variable following formulas that are changed to:

(definition normalization output during normal temperature)

(a) formula brought into:

$\frac{\mathrm{Sn}-100}{100}R2-R1=\mathrm{Rn}$

(b) formula is comprehensive gets:

$R2=(\frac{\mathrm{ScRh}-\mathrm{ShRc}}{\mathrm{Sh}-\mathrm{Sc}}+\mathrm{Rn})\frac{100}{\mathrm{Sn}}\·\·\·\·\·\·\left(1\right)$

Get with (b) formula is comprehensive again:

$R1=\left(\frac{\mathrm{ScRh}-\mathrm{ShRc}}{\mathrm{Sh}-\mathrm{Sc}}\right)-(\frac{\mathrm{ScRh}-\mathrm{ShRc}}{\mathrm{Sh}-\mathrm{Sc}}+\mathrm{Rn})\frac{100}{\mathrm{Sn}}$

If: substitute Rn and Sn with Rc and Sc, then (1) formula becomes:

$R2=\frac{100(\mathrm{Rh}-\mathrm{Rc})}{\mathrm{Sh}-\mathrm{Sc}}$

If: substitute Rn and Sn with Rh and Sh, then (1) formula becomes:

$R2=\frac{100(\mathrm{Rh}-\mathrm{Rc})}{\mathrm{Sh}-\mathrm{Sc}}$

Two kinds come to the same thing, then are reduced to:

$R1=\frac{\mathrm{ScRh}-\mathrm{ShRc}}{\mathrm{Sh}-\mathrm{Sc}}-\frac{100(\mathrm{Rh}-\mathrm{Rc})}{\mathrm{Sh}-\mathrm{Sc}}=\frac{\mathrm{ScRh}-\mathrm{ShRc}-100(\mathrm{Rh}-\mathrm{Rc})}{\mathrm{Sh}-\mathrm{Sc}}\·\·\·\·\·\·\left(3\right)$

Simplify: (1) is full formula, and (2) and (3) are formula of reduction.

As long as event tests out each parameter of sensor under the high low temperature, can calculate the value of R1 and R2, by laser resistor trimming, the resistance that is solidificated on the thick film circuit is adjusted to desired value, can the full scale temperature characterisitic and the full scale output of sensor be compensated, through the reality test, the full scale temperature characterisitic is adjusted effect and was not changed in the past, and the normalization output accuracy can reach ± 1%FS.

As shown in Figure 3, because sensor output and sensor power supply (constant pressure source power supply) are directly proportional, so:

Annotate: 1, S ' compensation back sensor full scale output; The output of S compensation front sensor full scale

2, constant current source is still used in the sensor performance test, and becoming the constant pressure source powered sensor after the compensation has according to condition 1 Sc=Sh:

Can get: $\frac{R1R2}{R1+R2}=\frac{\mathrm{ScSh}-\mathrm{ShSc}}{\mathrm{Sh}-\mathrm{Sc}}\·\·\·\·\·\·\left(1\right)$

Have according to condition 2: S '=100mV (E=10VDC), can get:

Order:

So: S R2=K R (R1+R2)+KR1 R2

The high low temperature subscript of substitution:

Sh□R2＝K□Rh(R1+R2)+KR1□R2

Sc□R2＝K□Rc(R1+R2)+KR1□R2

Two formulas differ:

$\frac{R2}{R1+R2}=\frac{K(\mathrm{Rh}-\mathrm{Rc})}{\mathrm{Sh}-\mathrm{Sc}}\·\·\·\·\·\·\left(2\right)$

(1) formula/(2) formula gets:

(wherein

)

Substitution (2) formula gets:

As long as event tests out each parameter of sensor under the high low temperature, can calculate the value of R1 and R2, by laser resistor trimming, the resistance that is solidificated on the thick film circuit is adjusted to desired value, can the full scale temperature characterisitic and the full scale output of sensor be compensated, through the reality test, the full scale temperature characterisitic is adjusted effect and was not changed in the past, and the normalization output accuracy can reach ± 1%FS.

Claims (1)

1. the normalization compensation method of a diffusion silicon pressure sensor, comprise diffuse si sensor bridge type circuit, it is characterized in that be connected in series first resistance R 1 at bridge type circuital current input end or voltage input end earlier, it is in parallel with first resistance R 1 and bridge type circuit that second resistance R 2 is set then.

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