Gas dew point detector calibration method

Abstract

The invention discloses a gas dew point detector calibration method, which comprises the following steps of: S1, generating a coordinate system by taking a sensor measurement temperature as an x axis and an actual measurement temperature as a y axis, and calculating a coordinate system by taking a sensor measurable lowest temperature, namely an actual lowest temperature and a sensor measurable highest temperature, the actual highest temperature generates a linear function for the two measurement points as an initial temperature calculation function; s2, using industrial gas with known temperature as standard test gas to pass through the dew point detector; s3, recording the temperature of the standard test gas and the temperature measured by the corresponding sensor, and marking as measuring points; s4, taking the measurement point and two adjacent measurement points as end points to generate two linear functions to replace an initial temperature calculation function; s5, multiple times of measurement are carried out at the suspected sensor precision drift point to improve the precision, the fitting function is used for offsetting errors, the application range is wide, operation is easy and convenient, the calibration time is shortened, and the labor cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of instrument calibration, and particularly to a calibration method for a gas dew point detector. Background Art

[0002] Currently, precise gas dew point detectors are relatively expensive, and the temperature sensors used to measure gases will inevitably have problems of accuracy drift, resulting in the temperature measured by the sensor not matching the actual temperature. Frequent replacement of the detector is uneconomical and unrealistic. Nowadays, in the field of gas dew point detectors, the method of manually recording points is mostly used to calibrate the dew point detector, which is not only time-consuming and laborious, but also requires special personnel to operate, and has relatively high technical requirements for the operators. Therefore, there is an urgent need to develop a calibration method for gas dew point detectors to solve the above technical problems.

[0003] In view of this, the present invention is specifically proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a calibration method for a gas dew point detector, which uses a fitting function to offset errors. The fitting function can be applied to any temperature within the measurement range, not only has a wide application range, but also is simple and convenient to operate, reduces the calibration time, saves labor costs, has a broad application prospect, and is conducive to popularization and application.

[0005] In order to achieve the above purpose, a calibration method for a gas dew point detector provided by the present invention includes the following steps:

[0006] S1: Generate a coordinate system with the temperature measured by the sensor as the x-axis and the actual measured temperature as the y-axis. Use the lowest temperature that the sensor can measure, that is, the actual lowest temperature, and the highest temperature that the sensor can measure, that is, the actual highest temperature (since sensor accuracy drift rarely occurs at both ends, the lowest temperature that the sensor can measure is equal to the actual lowest temperature, and the highest temperature that the sensor can measure is equal to the actual highest temperature) as two measurement points to generate a linear function as the initial temperature calculation function;

[0007] S2: Use an industrial gas with a known temperature as a standard test gas to pass through the dew point detector;

[0008] S3: Record the temperature of the standard test gas and the corresponding temperature measured by the sensor, and mark them as measurement points;

[0009] S4: Use these measurement points and the two adjacent measurement points as endpoints to generate two linear functions to replace the initial temperature calculation function;

[0010] S5: Measure multiple times at the suspected points of sensor accuracy drift, and add multiple measurement points according to requirements to improve the accuracy.

[0011] Preferably, in the step S2, the dew point detector is a CNL-104C portable dew point detector.

[0012] Preferably, in the step S2, the standard test gas is ammonia or liquefied petroleum gas.

[0013] Preferably, the method is applicable to a gas dew point detector with temperature measurement drift occurring in a certain temperature range.

[0014] A calibration method for a gas dew point detector provided by the present invention has the following beneficial effects.

[0015] 1. The operation of the present invention is simple and convenient, reducing the calibration time and saving labor costs.

[0016] 2. The present invention uses a fitting function to offset errors, and the fitting function can be applicable to any temperature within the measurement range, with a wide application range.

[0017] 3. The zero drift of the gas dew point detector often occurs in the middle section of the temperature detection range, and it is basically a parallel drift within a certain range, which is very suitable for being represented by a piecewise linear function. Moreover, the generation of the piecewise linear function does not require too many sampling points, and untrained personnel can also quickly get started. Description of the Drawings

[0018] Figure 1 is the initial temperature calculation function;

[0019] Figure 2 is the calculation function after the first addition of a calibration point;

[0020] Figure 3 is the calculation function after multiple additions of calibration points. Detailed Embodiments

[0021] The following further describes the present invention in conjunction with specific embodiments and drawings to help understand the content of the present invention.

[0022] A calibration method for a gas dew point detector provided by the present invention includes the following steps:

[0023] S1: Generate a coordinate system with the temperature measured by the sensor as the x-axis and the actual measured temperature as the y-axis. Use the lowest temperature that the sensor can measure, that is, the actual lowest temperature, and the highest temperature that the sensor can measure, that is, the actual highest temperature (since the sensor accuracy drift usually does not occur at both ends, the lowest temperature that the sensor can measure is equal to the actual lowest temperature, and the highest temperature that the sensor can measure is equal to the actual highest temperature) as two measurement points to generate a linear function as the initial temperature calculation function;

[0024] S2: Pass an industrial gas at a known temperature through the dew point detector as a standard test gas; preferably, the dew point detector is a CNL-104C portable dew point detector. In S2, the standard test gas is ammonia or liquefied petroleum gas.

[0025] S3: Record the temperature of the standard test gas and the temperature measured by the corresponding sensor, and mark them as measurement points;

[0026] S4: Generate two linear functions with these measurement points and the two adjacent measurement points as endpoints respectively to replace the initial temperature calculation function;

[0027] S5: Measure multiple times at the points suspected of sensor accuracy drift, and add multiple measurement points as needed to improve accuracy.

[0028] The method is applicable to gas dew point detectors with temperature measurement drift occurring in a certain temperature range. Use the lowest temperature measurable by the sensor, i.e., the actual lowest temperature, and the highest temperature measurable by the sensor, i.e., the actual highest temperature, as two measurement points to generate a linear function. As Figure 1 shown, it is the initial temperature calculation function. Pass an industrial gas, liquefied petroleum gas, at a known temperature through the dew point detector, record the temperature of the standard test gas and the temperature measured by the corresponding sensor, and mark them as measurement points. Generate two linear functions with these measurement points and the two adjacent measurement points as endpoints respectively to replace the initial temperature calculation function. As Figure 2 shown, it is the calculation function after the first addition of calibration points. Add measurement points multiple times as needed to generate a calculation function composed of multiple linear functions. As Figure 3 shown, it is the calculation function after multiple additions of calibration points.

[0029] The operation of the present invention is simple and convenient, reducing the calibration time and saving labor costs. The present invention uses a fitting function to offset errors. The fitting function can be applied to any temperature within the measurement range, with a wide application range. The zero drift of the gas dew point detector often occurs in the middle section of the temperature detection range, and it is basically a parallel drift within a certain range, which is very suitable for being represented by a piecewise linear function. And the generation of the piecewise linear function does not require too many sampling points, and even untrained personnel can quickly get started.

[0030] Specific examples are used in this article to elaborate on the inventive concept in detail. The description of the above embodiments is only used to help understand the core idea of the present invention. It should be noted that for those of ordinary skill in the art of this technology, any obvious modification, equivalent replacement, or other improvement made without departing from the inventive concept should be included in the protection scope of the present invention.

Claims

1. A calibration method for a gas dew point detector, characterized in that It includes the following steps: S1: Generate a coordinate system with the temperature measured by the sensor as the x-axis and the actually measured temperature as the y-axis. Use the lowest temperature measurable by the sensor, i.e., the actual lowest temperature, and the highest temperature measurable by the sensor, i.e., the actual highest temperature, as two measurement points to generate a linear function as the initial temperature calculation function; S2: Use an industrial gas with a known temperature as a standard test gas to pass through the dew point detector; S3: Record the temperature of the standard test gas and the corresponding temperature measured by the sensor, and mark them as measurement points; S4: Use the two linear functions generated with these measurement points and the adjacent two measurement points as endpoints respectively to replace the initial temperature calculation function; S5: Measure multiple times at the points suspected of sensor accuracy drift, and add multiple measurement points according to requirements to improve accuracy.

2. The calibration method of a gas dew point detector according to claim 1, characterized in that, In S2, the dew point detector is a CNL-104C portable dew point detector.

3. A calibration method for a gas dew point detector according to claim 2, characterized in that, In S2, the standard test gas is ammonia or liquefied petroleum gas.

4. A calibration method for a gas dew point detector according to claim 3, characterized in that, The method is applicable to a gas dew point detector with temperature measurement drift occurring in a certain temperature range.

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