CN-121977748-A - Calibration method, device and system of heating type capacitance film vacuum gauge

CN121977748ACN 121977748 ACN121977748 ACN 121977748ACN-121977748-A

Abstract

The application relates to the technical field of vacuum gauge calibration, in particular to a calibration method, equipment and a system of a heating type capacitance film vacuum gauge, wherein the calibration method comprises the steps of preheating the vacuum gauge until the internal temperature of the vacuum gauge reaches a stable state; the method comprises the steps of acquiring current temperature data of a vacuum gauge after the vacuum gauge reaches a stable state, acquiring a capacitance differential voltage value, calculating to obtain a temperature compensation value based on the capacitance differential voltage value, the current temperature data and a pre-stored temperature calibration coefficient, calculating to obtain a calibrated output digital quantity based on the temperature compensation value and the pre-stored linear calibration coefficient, converting the output digital quantity into an analog voltage output value, judging whether an output error of the analog voltage output value accords with preset precision, outputting a calibration completion signal if the output error accords with the preset precision, carrying out temperature compensation on the capacitance film vacuum gauge by utilizing the acquisition of a temperature signal, and effectively correcting errors such as capacitance characteristic offset, electrode deformation abnormality and the like caused by temperature fluctuation to obtain the capacitance film vacuum gauge with high precision and high stability.

Inventors

WANG FENGSHUANG
XIAO HUI
LIU QIAO
HOU SHAOYI
GUO WEIJIAN
YUN XIAOQI

Assignees

季华实验室

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. The calibration method of the heating type capacitance film vacuum gauge is characterized by comprising the following steps: preheating the vacuum gauge until the internal temperature reaches a stable state; collecting current temperature data of the vacuum gauge after the vacuum gauge reaches a stable state and obtaining a capacitance differential voltage value; calculating a temperature compensation value based on the capacitance differential voltage value, the current temperature data and a pre-stored temperature calibration coefficient; calculating to obtain a calibrated output digital quantity based on the temperature compensation value and a pre-stored linear calibration coefficient; and converting the output digital quantity into an analog voltage output value, judging whether the output error of the analog voltage output value accords with the preset precision, and if so, outputting a calibration completion signal.
2. The method for calibrating a heated capacitance diaphragm gauge according to claim 1, wherein the preheating of the gauge is performed until the internal temperature reaches a steady state, and comprises: Heating the vacuum gauge according to preset time; Acquiring temperature data inside the vacuum gauge at a fixed frequency to obtain a temperature dataset; calculating according to the temperature data set to obtain a temperature change rate; Judging whether the heating time reaches the preset time and whether the temperature change rate is lower than a preset threshold value, if so, determining that the internal temperature reaches a stable state.
3. The method for calibrating a heated type capacitance film vacuum gauge according to claim 1, wherein the step of obtaining the capacitance differential voltage value comprises the following steps: Respectively collecting voltage signals of capacitors at two sides of the vacuum gauge; differential amplification is carried out on the voltage signals at two sides so as to obtain differential voltage analog signals; normalizing the differential voltage analog signal to obtain a normalized voltage signal; and carrying out digital quantization on the normalized voltage signal to obtain a capacitance differential voltage value.
4. The method for calibrating a heated capacitor film vacuum gauge according to claim 1, wherein the step of converting the output digital value into an analog voltage output value and determining whether an output error of the analog voltage output value meets a preset precision, and if so, outputting a calibration complete signal further comprises: and converting the output digital quantity into analog voltage output, judging whether the output error of the analog voltage output accords with preset precision, and if not, returning to the acquisition of the current temperature data of the vacuum gauge after reaching a stable state and acquiring a capacitance differential voltage value.
5. The method for calibrating a heated type capacitance film vacuum gauge according to claim 1, wherein the calculating the temperature compensation value based on the capacitance differential voltage value, the current temperature data and the pre-stored temperature calibration coefficient comprises the following steps: Extracting a pre-stored temperature calibration coefficient to obtain a first calibration parameter, a second calibration parameter and a third calibration coefficient; Determining a temperature bias parameter based on the current temperature data; Calculating a temperature compensation value by using a compensation formula based on the current temperature data, the first calibration parameter, the second calibration parameter, the third calibration parameter and the temperature bias coefficient; wherein the compensation formula is t=t 0 +（T d -K 0 K 1 [0.5+K 3 (K d -k 0 ) K 1 ], wherein T is a temperature compensation value, K 0 is a first calibration parameter, K 1 is a second calibration parameter, K 3 is a third calibration parameter, T 0 is a normal temperature value, T d is a real-time temperature value, and K d is a temperature bias coefficient.
6. The method for calibrating a heated capacitor film vacuum gauge according to claim 1, wherein the converting the output digital value into an analog voltage output value and determining whether an output error of the analog voltage output value meets a preset precision, and if so, outputting a calibration complete signal, comprises: converting the output digital quantity to obtain an initial analog voltage; Amplifying and filtering the initial analog voltage to obtain an analog voltage output value; Calculating a theoretical voltage value corresponding to the analog voltage output value and the standard pressure value to obtain an error percentage between the analog voltage output value and the standard pressure value; And judging whether the error percentage is smaller than a preset threshold value, if so, judging that the error percentage meets the preset precision, and outputting a calibration completion signal.
7. The method for calibrating a heated type capacitance film vacuum gauge according to claim 1, wherein the calculating the calibrated output digital quantity based on the temperature compensation value and the pre-stored linear calibration coefficient comprises: calculating to obtain an intermediate value based on the temperature compensation value and a pre-stored linear calibration coefficient; Performing linear conversion on the intermediate value to obtain an output value; the output value is converted to obtain an output digital quantity.
8. A calibration device characterized by comprising: a controller for performing the calibration method of the heated capacitance thin film vacuum gauge of claim 1.
9. The calibration apparatus of claim 8, further comprising: a sensor cavity; a capacitive pressure sensor disposed within the sensor cavity; the excitation module is electrically connected with the capacitive pressure sensor and is used for outputting an excitation signal to the capacitive pressure sensor; the heating device is arranged on the sensor cavity; and the signal processing device is electrically connected with the controller and is used for outputting a linearization voltage signal.
10. A calibration system, comprising: a vacuum gauge and a calibration device as claimed in claim 8 or 9, with which the vacuum gauge is calibrated.

Description

Calibration method, device and system of heating type capacitance film vacuum gauge Technical Field The application relates to the technical field of vacuum gauge calibration, in particular to a calibration method, equipment and a system of a heating type capacitance film vacuum gauge. Background The capacitance film vacuum gauge measures pressure by detecting capacitance change caused by deformation of the pressure sensing film under pressure, and has the advantages of high measurement accuracy, good stability, independence of gas types and the like. However, its measurement accuracy is extremely susceptible to changes in ambient temperature. The temperature change can cause thermal stress deformation of the pressure sensing film, gas state change in the sensor and parameter drift of circuit elements, so that obvious measurement errors are introduced. Existing vacuum gauges typically employ a simple temperature sensor for first order linear compensation for errors or calibration at constant room temperature. The method is difficult to cope with complex nonlinear temperature effects in a wide temperature range, and calibration can lead to deviation of calibration parameters when the sensor does not reach a thermal equilibrium state, so that the vacuum gauge has poor measurement linearity and insufficient stability at actual working temperature. Disclosure of Invention The present application aims to improve at least one technical problem in the background art. The application provides a calibration method of a heating type capacitance film vacuum gauge, which comprises the following steps: preheating the vacuum gauge until the internal temperature reaches a stable state; collecting current temperature data of the vacuum gauge after the vacuum gauge reaches a stable state and obtaining a capacitance differential voltage value; calculating a temperature compensation value based on the capacitance differential voltage value, the current temperature data and a pre-stored temperature calibration coefficient; calculating to obtain a calibrated output digital quantity based on the temperature compensation value and a pre-stored linear calibration coefficient; and converting the output digital quantity into an analog voltage output value, judging whether the output error of the analog voltage output value accords with the preset precision, and if so, outputting a calibration completion signal. According to some technical schemes of the application, the vacuum gauge is preheated until the internal temperature reaches a stable state, and the method specifically comprises the following steps: Heating the vacuum gauge according to preset time; Acquiring temperature data inside the vacuum gauge at a fixed frequency to obtain a temperature dataset; calculating according to the temperature data set to obtain a temperature change rate; Judging whether the heating time reaches the preset time and whether the temperature change rate is lower than a preset threshold value, and if so, determining that the internal temperature reaches a stable state. According to some technical schemes of the application, the method for obtaining the capacitance differential voltage value specifically comprises the following steps: Respectively collecting voltage signals of capacitors at two sides of the vacuum gauge; differential amplification is carried out on the voltage signals at two sides so as to obtain differential voltage analog signals; normalizing the differential voltage analog signal to obtain a normalized voltage signal; and carrying out digital quantization on the normalized voltage signal to obtain a capacitance differential voltage value. According to some embodiments of the present application, the method further includes, after converting the output digital quantity into an analog voltage output value and determining whether an output error of the analog voltage output value meets a preset precision, if yes, outputting a calibration completion signal: and converting the output digital quantity into analog voltage output, judging whether the output error of the analog voltage output accords with preset precision, and if not, returning to the acquisition of the current temperature data of the vacuum gauge after reaching a stable state and acquiring a capacitance differential voltage value. According to some technical schemes of the application, the temperature compensation value is calculated based on the capacitance differential voltage value, the current temperature data and the pre-stored temperature calibration coefficient, and the method specifically comprises the following steps: Extracting a pre-stored temperature calibration coefficient to obtain a first calibration parameter, a second calibration parameter and a third calibration coefficient; Determining a temperature bias parameter based on the current temperature data; Calculating a temperature compensation value by using a compensation formula based on the current t