阅读说明：本技术 压力传感器的补偿方法和系统 (Pressure sensor compensation method and system ) 是由 王瑞 牟昌华 何漫丽 于 2019-10-11 设计创作，主要内容包括：本发明提供一种压力传感器的补偿方法和系统,该方法包括：S1,在压力传感器的量程范围内选取多个设定压力值,获取相应的压力值组,每一压力值组均包括设定温度值下的不同输出压力值,零点压力值对应的压力值组为压力传感器的零点压力值组；S2,对输出压力值进行拟合,获得各设定温度值的零点修正值,基于零点修正值对各压力值组中的输出压力值进行零点修正；S3,对经过零点修正的输出压力值进行二次曲线拟合,获得温度补偿曲线；S4,对温度补偿曲线进行最小二乘法曲线拟合,获得压力传感器的标定补偿曲线,基于标定补偿曲线对输出压力值进行标定补偿。本发明提供的压力传感器的补偿方法和系统,补偿精度高、系统资源消耗少,且标定周期短。(The invention provides a compensation method and a system of a pressure sensor, wherein the method comprises the following steps: s1, selecting a plurality of set pressure values in the measuring range of the pressure sensor, and acquiring corresponding pressure value groups, wherein each pressure value group comprises different output pressure values under set temperature values, and the pressure value group corresponding to the zero pressure value is the zero pressure value group of the pressure sensor; s2, fitting the output pressure values to obtain zero correction values of the set temperature values, and performing zero correction on the output pressure values in the pressure value sets based on the zero correction values; s3, performing quadratic curve fitting on the output pressure value subjected to zero point correction to obtain a temperature compensation curve; and S4, performing least square curve fitting on the temperature compensation curve to obtain a calibration compensation curve of the pressure sensor, and performing calibration compensation on the output pressure value based on the calibration compensation curve. The compensation method and the compensation system for the pressure sensor have the advantages of high compensation precision, low system resource consumption and short calibration period.)

1. A method of compensating a pressure sensor, comprising the steps of:

s1, selecting a plurality of set pressure values in the range of the pressure sensor, and acquiring pressure value groups corresponding to the plurality of set pressure values one by one, wherein each pressure value group comprises different output pressure values of the pressure sensor at different set temperature values of the set pressure value corresponding to the pressure value group, the plurality of set pressure values comprise zero pressure values of the pressure sensor, and the pressure value group corresponding to the zero pressure value is the zero pressure value group of the pressure sensor;

S2, fitting the output pressure values in the zero pressure value groups to obtain a zero correction value of each set temperature value, and performing zero correction on the output pressure values in the pressure value groups based on the zero correction value;

S3, performing quadratic curve fitting on the output pressure values corrected by the zero-crossing point in each pressure value group to obtain a temperature compensation curve of the pressure sensor;

And S4, performing least square curve fitting on the temperature compensation curve to obtain a calibration compensation curve of the pressure sensor, and performing calibration compensation on the output pressure value of the pressure sensor based on the calibration compensation curve.

2. The method of compensating a pressure sensor of claim 1, wherein said selecting a plurality of set pressure values over a range of span of said pressure sensor comprises:

Dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different full-scale percentages as segmentation points, and respectively selecting the set pressure values in the sub-ranges, wherein the smaller the pressure value corresponding to the sub-range is, the more the number of the set pressure values selected in the sub-range is.

3. the method of compensating a pressure sensor according to claim 2, wherein the span range of the pressure sensor is divided into two sub-ranges by using 20% of the full span as a segmentation point;

within the sub-range below the segmentation point, the number of the selected set pressure values is greater than or equal to 3.

4. the method of compensating a pressure sensor of claim 1, wherein said least squares curve fitting said temperature compensation curve comprises:

Dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different percentages of full measuring range as segmentation points, and performing curve fitting on the temperature compensation curve by adopting a least square method with different orders for different sub-ranges.

5. The method of compensating a pressure sensor of claim 4, wherein said least squares curve fitting said temperature compensation curve comprises:

Dividing the measuring range of the pressure sensor into two sub-ranges by taking 20% of full range as a segmentation point;

for the sub-range lower than the segmentation point, performing curve fitting on the temperature compensation curve by adopting a 5-order least square method;

And for the sub-range higher than the segmentation point, performing curve fitting on the temperature compensation curve by using a 3-order least square method.

6. the method for compensating a pressure sensor according to any one of claims 1 to 5, further comprising, after the step S4, the steps of:

And S5, dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different full-scale percentages as segmentation points, selecting at least one detection pressure value in each sub-range, judging whether the error between the compensated output pressure value output by the pressure sensor and the detection pressure value under the detection pressure value is larger than a preset threshold value, if so, setting an adjusting coefficient for the sub-range corresponding to the detection pressure value, and calibrating the compensated output pressure value again based on the adjusting coefficient when the compensated output pressure value output by the pressure sensor is in the sub-range.

7. The method for compensating a pressure sensor according to claim 4 or 5, wherein in the step S3, the formula corresponding to the temperature compensation curve is as follows:

P＝(Q-Z)(rT²+qT+u)

wherein P is the output pressure value after temperature compensation, Q is the output pressure value, Z is the zero correction value, (rT ² + qT + u) is the temperature coefficient, r, Q and T are constants, and T is the actual temperature value.

8. The method for compensating a pressure sensor according to claim 7, wherein in the step S4, for the sub-range lower than the segmentation point, the formula of the calibration compensation curve is:

Pout＝aP⁵+bP⁴+cP³+dP²+eP+f

For the sub-range above the segmentation point, the formula of the calibration compensation curve is:

Pout＝aP³+bP²+cP+d

wherein, Pout is the output pressure value after calibration compensation; a. b, c, d, e and f are calibration factors.

9. a compensation system for a pressure sensor, comprising:

A control unit for compensating the pressure sensor by using the compensation method of the pressure sensor according to any one of claims 1 to 8;

The temperature control unit is used for adjusting the working temperature of the pressure sensor under the control of the control unit;

and the pressure control unit is used for adjusting the actual pressure detected by the pressure sensor under the control of the control unit.

10. the compensation system for a pressure sensor of claim 9, further comprising:

And the multi-path connecting unit is used for connecting the pressure control unit and one or more pressure sensors.

Technical Field

The invention relates to the technical field of flowmeters, in particular to a compensation method and a compensation system for a pressure sensor.

Background

The pressure sensor is a core component of a pressure type gas Mass Flow Controller (Mass Flow Controller, hereinafter referred to as MFC), and the output precision of the pressure sensor plays a decisive role in the control precision of the pressure type MFC. There are two main types of pressure sensors: resistive and capacitive sensors, both of which tend to have a bias in the output signal of the pressure sensor and have a temperature-dependent drift characteristic due to manufacturing material and process issues. Therefore, temperature compensation including zero point temperature compensation, sensitivity temperature compensation, and accuracy calibration at normal temperature needs to be performed on the pressure sensor to ensure that the pressure sensor can output a signal satisfying the accuracy requirement within a certain temperature range.

The existing temperature compensation methods are two, one is an analog compensation method, which reduces the influence of temperature on the output of a pressure sensor by respectively connecting passive devices such as a resistor, a capacitor and the like in series and in parallel at the input end and the output end of the pressure sensor so as to perform voltage division or shunt. The other is a digital compensation method, which obtains an output signal of the pressure sensor through a digital or analog circuit, analyzes the output signal, and then digitally compensates the output signal of the pressure sensor according to the analysis result. If the compensation method adopts a simple algorithm for analysis, although the calibration period is short, the compensation precision is low; if a complex algorithm is adopted for analysis, although the compensation precision is high, the problems of large system consumption and large data storage amount exist, in addition, in order to obtain a correct mathematical model, data under different temperatures need to be collected, the data amount is large, and the calibration period is long.

Therefore, a compensation method and system with high compensation accuracy, low system resource consumption and short calibration period are needed.

Disclosure of Invention

the invention aims to at least solve one of the technical problems in the prior art and provides a compensation method and a compensation system of a pressure sensor, which have the advantages of high compensation precision, low system resource consumption and short calibration period.

In order to achieve the above object, the present invention provides a compensation method of a pressure sensor, comprising the steps of:

s1, selecting a plurality of set pressure values in the range of the pressure sensor, and acquiring pressure value groups corresponding to the plurality of set pressure values one by one, wherein each pressure value group comprises different output pressure values of the pressure sensor at different set temperature values of the set pressure value corresponding to the pressure value group, the plurality of set pressure values comprise zero pressure values of the pressure sensor, and the pressure value group corresponding to the zero pressure value is the zero pressure value group of the pressure sensor;

s2, fitting the output pressure values in the zero pressure value groups to obtain a zero correction value of each set temperature value, and performing zero correction on the output pressure values in the pressure value groups based on the zero correction value;

s3, performing quadratic curve fitting on the output pressure values corrected by the zero-crossing point in each pressure value group to obtain a temperature compensation curve of the pressure sensor;

And S4, performing least square curve fitting on the temperature compensation curve to obtain a calibration compensation curve of the pressure sensor, and performing calibration compensation on the output pressure value of the pressure sensor based on the calibration compensation curve.

optionally, selecting a plurality of set pressure values within the range of the measuring range of the pressure sensor includes:

dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different full-scale percentages as segmentation points, and respectively selecting the set pressure values in the sub-ranges, wherein the smaller the pressure value corresponding to the sub-range is, the more the number of the set pressure values selected in the sub-range is.

optionally, dividing the measuring range of the pressure sensor into two sub-ranges by taking 20% of the full measuring range as a segmentation point;

Within the sub-range below the segmentation point, the number of the selected set pressure values is greater than or equal to 3.

Optionally, the performing least squares curve fitting on the temperature compensation curve includes:

Dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different percentages of full measuring range as segmentation points, and performing curve fitting on the temperature compensation curve by adopting a least square method with different orders for different sub-ranges.

optionally, the performing least squares curve fitting on the temperature compensation curve includes:

Dividing the measuring range of the pressure sensor into two sub-ranges by taking 20% of full range as a segmentation point;

for the sub-range lower than the segmentation point, performing curve fitting on the temperature compensation curve by adopting a 5-order least square method;

And for the sub-range higher than the segmentation point, performing curve fitting on the temperature compensation curve by using a 3-order least square method.

Optionally, after the step S4, the method further includes the following steps:

And S5, dividing the measuring range of the pressure sensor into a plurality of sub-ranges by taking one or more different full-scale percentages as segmentation points, selecting at least one detection pressure value in each sub-range, judging whether the error between the compensated output pressure value output by the pressure sensor and the detection pressure value under the detection pressure value is larger than a preset threshold value, if so, setting an adjusting coefficient for the sub-range corresponding to the detection pressure value, and calibrating the compensated output pressure value again based on the adjusting coefficient when the compensated output pressure value output by the pressure sensor is in the sub-range.

optionally, in step S3, the formula corresponding to the temperature compensation curve is:

P＝(Q-Z)(rT²+qT+u)

wherein P is the output pressure value after temperature compensation, Q is the output pressure value, Z is the zero correction value, (rT ² + qT + u) is the temperature coefficient, r, Q and T are constants, and T is the actual temperature value.

optionally, in step S4, for the sub-range lower than the segmentation point, the formula of the calibration compensation curve is:

Pout＝aP⁵+bP⁴+cP³+dP²+eP+f

for the sub-range above the segmentation point, the formula of the calibration compensation curve is:

Pout＝aP³+bP²+cP+d

Wherein, Pout is the output pressure value after calibration compensation; a. b, c, d, e and f are calibration factors.

As another technical solution, the present invention also provides a compensation system of a pressure sensor, including:

The control unit is used for compensating the pressure sensor by adopting the compensation method of the pressure sensor provided by the invention;

The temperature control unit is used for adjusting the working temperature of the pressure sensor under the control of the control unit;

and the pressure control unit is used for adjusting the actual pressure detected by the pressure sensor under the control of the control unit.

Optionally, the method further includes:

And the multi-path connecting unit is used for connecting the pressure control unit and one or more pressure sensors.

the invention has the beneficial effects that:

according to the technical scheme of the compensation method and the compensation system of the pressure sensor, only a certain number of pressure value groups need to be acquired, wherein each pressure value group corresponds to the set pressure value selected in the measuring range one by one, each pressure value group comprises different output pressure values of the pressure sensor at different set temperature values of the set pressure value corresponding to the pressure value group, and the plurality of set pressure values comprise zero-point pressure value groups of the pressure sensor. By fitting the output pressure values in the zero-point pressure value groups, the zero-point correction of the output pressure values in each output pressure value group can be performed based on the zero-point correction value obtained by the fitting. And then, carrying out quadratic curve fitting on the output pressure values corrected by the zero point in each pressure value group, namely realizing temperature compensation. And finally, performing least square curve fitting on the temperature compensation curve obtained by quadratic curve fitting to obtain a calibration compensation curve, and further performing calibration compensation on the output pressure value of the pressure sensor based on the obtained calibration compensation curve.

Compared with the prior art, the compensation method and the compensation system for the pressure sensor have the advantages that the zero point correction, the temperature compensation and the precision calibration are carried out by adopting the corresponding fitting method, the compensation precision is higher, and a large amount of data does not need to be acquired, so that the resource consumption of the system is reduced, and the calibration period is shortened.

Drawings

FIG. 1 is a block flow diagram of a method for compensating a pressure sensor according to an embodiment of the present invention;

FIG. 2 is a block diagram of a compensation system for a pressure sensor provided in accordance with an embodiment of the present invention;

Fig. 3 is a structural diagram of a pressure-type MFC employed in an embodiment of the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following describes the compensation method and system of the pressure sensor in detail with reference to the accompanying drawings.

referring to fig. 1, a compensation method for a pressure sensor according to an embodiment of the present invention includes the following steps:

S1, selecting a plurality of set pressure values in the range of the pressure sensor, and acquiring pressure value groups corresponding to the set pressure values one by one, wherein each pressure value group comprises different output pressure values of the pressure sensor at different set temperature values corresponding to the pressure value group, the plurality of set pressure values comprise zero pressure values of the pressure sensor, and the pressure value group corresponding to the zero pressure value is the zero pressure value group of the pressure sensor.

In step S1, the manner of selecting the set pressure value may specifically be: the pressure control device is used for directly adjusting the pressure value in a member to be pressure-detected (such as a fluid channel) to a specific value within the measuring range of the pressure sensor, and the specific value is the set pressure value. It will be readily appreciated that the accuracy of the adjustment of the pressure control means should be greater than the accuracy of the output of the pressure sensor.

The working temperature of the pressure sensor is adjusted by the temperature control device to reach a certain specific value, and the specific value is the temperature set value.

Under the condition of a certain temperature set value, the pressure in the component to be pressure-detected (such as a fluid channel) is adjusted to different set pressure values one by using the pressure control device, and the output pressure value fed back from the pressure sensor is correspondingly received, so that the output pressure value under the temperature set value in each pressure value group can be obtained. By repeating the above operations at different temperature set values, the output pressure values in the pressure value sets can be finally obtained.

Next, the above step S1 will be described in detail by taking 6 pressure value sets as an example. Specifically, as shown in table 1 below, first, 6 different set pressure values (P10-P15) and 4 different set temperature values (T1-T4) are selected within the range of the pressure sensor. Then, the working temperature of the pressure sensor is adjusted to a set temperature value by using the temperature control device, the pressure in the component to be pressure-detected is adjusted to a set pressure value by using the pressure control device, the output pressure value fed back by the pressure sensor is read after the pressure is stabilized, and the steps of temperature setting, pressure setting and pressure feedback are repeated in this way, so that 6 pressure value groups corresponding to 6 set pressure values (P10-P15) in a one-to-one manner can be obtained, for example, the pressure value group corresponding to the set pressure value P10 comprises 4 output pressure values (Q10-Q40) corresponding to 4 set temperature values (T1-T4) in a one-to-one manner.

the set pressure value P10 is a zero pressure value of the pressure sensor, that is, the set pressure value P10 is zero, and the pressure value group corresponding to the set pressure value P10 is the zero pressure value group of the pressure sensor.

table 1 shows 6 sets of pressure values.

in accordance with the temperature characteristic of the pressure sensor, in a low-pressure range (for example, a pressure range less than 20% of the full scale), the nonlinearity of the output pressure value is strong, which requires that the number of the set pressure values be increased within the range appropriately to ensure the accuracy of the subsequent linear fitting to meet the requirement.

Optionally, the range of the pressure sensor is divided into a plurality of sub-ranges by taking one or more different percentages of the full-scale range as a segmentation point, and set pressure values are respectively selected from the plurality of sub-ranges, the smaller the pressure value corresponding to the sub-range is, the more the number of the set pressure values selected from the sub-range is, that is, the number of the set pressure values selected from the low-pressure range should be greater than the number of the set pressure values selected from the high-pressure range.

for example, the range of the pressure sensor is divided into two sub-ranges with 20% of the full range as a segmentation point; wherein the number of selected set pressure values is greater than or equal to 3 in a sub-range (i.e., a low pressure range of 20% or less of full scale) below the segmentation point. The number can ensure that the accuracy of subsequent linear fitting can meet the requirement.

and S2, fitting the output pressure values in the zero pressure value groups to obtain the zero correction value of each set temperature value, and performing zero correction on the output pressure values in the pressure value groups based on the zero correction value.

optionally, the difference between each output pressure value and the corresponding zero correction value is the output pressure value subjected to zero correction.

Step S2 will be described in detail by taking the 6 pressure value groups in table 1 as an example. Specifically, as shown in table 2, it is assumed that the pressure value group (the second column data in table 2) corresponding to set pressure value P10 is a zero-point pressure value group.

First, 4 output pressure values (Q10-Q40) in the zero-point pressure value group are fitted to obtain a straight line or a curve, and zero-point correction values (Z10-Z40) corresponding to 4 set temperature values (T1-T4) one by one are obtained according to the straight line or the curve.

then, the difference between each output pressure value and the corresponding zero point correction value, i.e., the same set temperature value, in the 6 sets of pressure value groups is calculated group by group, and the same zero point correction value is subtracted from the output pressure values in the different sets of pressure value groups. For example, the set temperature value is T1, and the zero point correction value Z10 is subtracted from all of the output pressure values (Q10 to Q15) corresponding to T1 in the 6 pressure value groups. And obtaining the difference value which is the output pressure value after zero point correction, thereby finishing the zero point correction.

table 2 shows 6 sets of zero-point-corrected pressure value groups.

After the zero point correction is completed, the output pressure value subjected to the zero point correction is subjected to temperature compensation, namely:

And S3, performing quadratic curve fitting on the output pressure values corrected by the zero crossing point in each pressure value group to obtain a temperature compensation curve of the pressure sensor.

The temperature compensation curve can represent the corresponding relation between the output pressure value after temperature compensation and the actual temperature value.

step S3 will be described in detail with reference to the 6 pressure value groups in table 2. Specifically, quadratic curve fitting is performed on 4 output pressure values subjected to zero point correction in each pressure value group, that is, a compensation curve corresponding to each set temperature value is obtained by fitting, and then the compensation curves are fitted to obtain a final temperature compensation curve. For example, as shown in table 3, by performing quadratic curve fitting on the zero-point-corrected output pressure values of 4 pressure value groups corresponding to the set pressure value P10, the output pressure value at the actual temperature value Tx, that is, (Qx0-Zx0) Kx0, can be obtained. Wherein, (Qx0-Zx0) is the output pressure value after zero point correction; kx0 is the temperature coefficient. The formula corresponding to the temperature compensation curve is as follows:

P＝(Q-Z)(rT²+qT+u)

Wherein, P is the output pressure value after temperature compensation, Q is the output pressure value, Z is the zero point correction value, (Q-Z) is the difference, (rT ² + qT + u) is the temperature coefficient, r, Q and T are constants, and T is the actual temperature value.

In step S3, by performing quadratic curve fitting, the complexity of the algorithm can be reduced, so that on the premise of higher compensation accuracy, it is not necessary to collect a large amount of data, thereby reducing the system resource consumption and shortening the calibration period.

Table 3 shows 6 sets of pressure values after temperature compensation.

after finishing temperature compensation, carrying out precision calibration on the output pressure value after temperature compensation, namely:

And S4, performing least square curve fitting on the temperature compensation curve to obtain a calibration compensation curve of the pressure sensor, and performing calibration compensation on the output pressure value of the pressure sensor based on the calibration compensation curve.

In step S4, the least square curve fitting is performed, so that the complexity of the algorithm can be reduced, and a large amount of data does not need to be acquired on the premise of higher compensation accuracy, thereby reducing the system resource consumption and shortening the calibration period.

According to the temperature characteristics of the pressure sensor, the output pressure value has a strong nonlinearity in a low pressure range (for example, a pressure range of 20% or less of the full scale), and in order to ensure that the accuracy of the output signal in the low pressure range satisfies the requirement, it is necessary to perform a higher order least square curve fitting in the low pressure range, and it is sufficient to perform a lower order least square curve fitting in the high pressure range. That is, the range of the pressure sensor is divided into a plurality of sub-ranges by taking one or more different percentages of full range as a segmentation point, and the temperature compensation curve is subjected to curve fitting by adopting a least square method with different orders for different sub-ranges.

Optionally, the range of the pressure sensor is divided into two sub-ranges by taking 20% of the full range as a segmentation point; for the sub-range lower than the segmentation point, a 5 th order least square method is adopted to perform curve fitting on the temperature compensation curve, and optionally, the formula for calibrating the compensation curve is as follows:

Pout＝aP⁵+bP⁴+cP³+dP²+eP+f

For the sub-range higher than the segmentation point, a 3-order least square method is adopted to perform curve fitting on the temperature compensation curve, and optionally, the formula for calibrating the compensation curve is as follows:

Pout＝aP³+bP²+cP+d

Wherein, Pout is a pressure calibration value; p is a pressure compensation value; a. b, c, d, e and f are calibration factors.

For some applications of pressure sensors, for example, in pressure MFCs, since the pressure MFC has strict requirements on control accuracy, generally within 1% accuracy error, it is required that the pressure sensor has higher output accuracy in a low pressure range (5% -10% for 5% -100% full scale).

For this reason, optionally, after step S4, the following steps are further included:

S5, dividing the range of the pressure sensor into multiple sub-ranges by taking one or more different full-range percentages as segmentation points, selecting at least one detection pressure value in each sub-range, judging whether the error between the compensated output pressure value output by the pressure sensor and the detection pressure value is larger than a preset threshold value or not at the detection pressure value, if so, setting an adjustment coefficient for the sub-range corresponding to the detection pressure value, and calibrating the compensated output pressure value again based on the adjustment coefficient when the compensated output pressure value output by the pressure sensor is in the sub-range.

Assuming that the error is σ and the predetermined constant is g, the adjustment coefficient ∈ is σ × g, where the predetermined constant g may be obtained empirically.

By means of the step S5, the output accuracy error of the pressure sensor in the whole range can be within 1%, and the requirement of high accuracy in the semiconductor industry and the like can be met.

in summary, the compensation method for the pressure sensor provided by the embodiment of the present invention can implement zero point correction, temperature compensation and precision calibration for the pressure sensor, and compared with the prior art, the compensation method for the pressure sensor has higher compensation precision by performing the zero point correction, the temperature compensation and the precision calibration by using the corresponding fitting method, and does not need to acquire a large amount of data, thereby reducing system resource consumption and shortening the calibration period.

As another technical solution, an embodiment of the present invention further provides a compensation system for a pressure sensor, referring to fig. 2, the system includes a control unit 1, a temperature control unit 2, and a pressure control unit 3. The control unit 1 is configured to compensate the pressure sensor 4 by using the above compensation method for a pressure sensor provided in the embodiment of the present invention. The temperature control unit 2 is used to adjust the operating temperature of the pressure sensor 4 under the control of the control unit 1. The pressure control unit 3 is used to regulate the actual pressure detected by the pressure sensor.

Optionally, the temperature control unit 2 and the control unit 1 communicate in a wired or wireless manner, and the pressure control unit 3 and the control unit 1 communicate in a wired or wireless manner.

In the present embodiment, the pressure sensor 4 is applied in a mass flow controller, i.e., a pressure-type MFC5, for detecting a pressure in a fluid passage 52 (i.e., a member to be pressure-detected), and sending an output pressure value to a control module 51 of the pressure-type MFC 5; the control module 51 is in wired or wireless communication with the control unit 1, and is used for converting the analog signal of the output pressure value into a digital signal and sending the digital signal to the control unit 1; the pressure control unit 3 is used to regulate the actual pressure in the fluid passage 52.

in the present embodiment, referring to fig. 3, the pressure MFC5 specifically includes a control module 51, a fluid passage 52, a pressure valve driving unit 53, and a pressure valve 54. The control module 51 controls the opening of the pressure valve 54 through the pressure valve driving unit 53 to achieve regulation of the fluid flow rate in the fluid passage 52.

Optionally, as shown in fig. 2, the compensation system further includes a multiplexing unit 6; the multiplexing unit 6 is used to connect the pressure control unit 3 to the fluid channels 52 in one or more pressure sensors. The connections to the fluid passages 52 in both sets of pressure MFCs 5 are shown in fig. 2, although in practice a greater number of pressure MFCs 5 may be connected as may be required. Alternatively, a pressure-type MFC5 may be connected, and the multiplexing unit 6 is not required.

The compensation system of the pressure sensor provided by the embodiment of the invention can realize zero point correction, temperature compensation and precision calibration of the pressure sensor by adopting the compensation method provided by the embodiment of the invention, and compared with the prior art, the compensation system has higher compensation precision by adopting a corresponding fitting method to carry out zero point correction, temperature compensation and precision calibration, and does not need to acquire a large amount of data, thereby reducing the resource consumption of the system and shortening the calibration period.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.