CN106908197A - Bearing calibration is demarcated in a kind of pressure gauge temperature drift - Google Patents

Abstract

The present invention particularly relates to a method for calibrating and correcting the temperature drift of a manometer, comprising: S1, placing the calibrated manometer in an oven, connecting the piston manometer outside the oven through a communication device to complete the calibration of the pressure strain, and obtaining the calibrated pressure strain and the piston pressure The corresponding relationship between the standard pressure value of the gauge; S2, take the calibrated pressure gauge out of the oven, connect it directly to the piston pressure gauge, and after standing for a predetermined time, measure the corresponding data between the current calibrated pressure strain and the current standard pressure value under the current temperature conditions; S3 , substituting the current standard pressure value into the corresponding relationship under the current temperature condition to obtain the corrected and calibrated pressure strain amount, making a difference between the corrected and calibrated pressure strain amount and the current calibrated pressure strain amount, and the difference result is used as a communication device transmission error ; S4, using the transmission error to correct all the calibration pressure and strain variables to obtain the calibration pressure and strain calibration value, and calculate the calibration pressure through the calibration pressure-calibration pressure and strain volume fitting relationship.

Description

A Calibration Correction Method for Pressure Gauge Temperature Drift

technical field

The invention relates to the field of measurement, in particular to a method for calibrating and correcting pressure gauge temperature drift.

Background technique

In the field of pressure measurement, especially in the field of downhole pressure measurement in oil and gas fields, piezoresistive sensors or quartz sensors are usually used to collect front-end pressure. The above-mentioned sensors have obvious temperature drift phenomenon due to the use of semiconductor devices, so they all need to be corrected for temperature drift.

At present, the calibration and correction of pressure gauges, whether it is automatic or manual, requires the use of piston pressure gauges to provide standard pressure values for the system. In order to correct the temperature drift of the sensor, the entire pressure gauge must be placed in an oven to provide a constant ambient temperature for the pressure gauge through the oven. The piston pressure gauge is located outside the oven, and the calibrated pressure gauge and piston pressure gauge inside and outside the oven pass through the communication device connected.

The introduction of the communication device in the existing temperature drift calibration method also brings the transmission error in this link, which seriously affects the calibration accuracy of the final pressure gauge. In the existing temperature drift calibration method, the calibration work is completed after the calibration in the oven is completed, and the transfer error introduced by the communication device is not dealt with. Therefore, in order to obtain a high-precision pressure gauge, it is necessary to purchase a high-precision sensor regardless of the cost. Under the same precision requirements, the cost of use is greatly increased, and the precision performance of the sensor itself is not fully utilized. For the above reasons, the present invention provides another way to improve the measurement accuracy of the sensor, and optimizes the temperature drift calibration and correction method of the pressure gauge, so that under the same circumstances, the calibration accuracy can be greatly improved, and the cost of using the sensor can be reduced at the same time.

Contents of the invention

The purpose of the present invention is to overcome the existing temperature drift calibration technology for manometers using an oven to provide constant temperature conditions, and to connect the manometer to be calibrated inside and outside the oven with the piston manometer through a connecting device to introduce the transmission error problem of the communication device. By optimizing the pressure The temperature drift calibration method of the pressure gauge improves the calibration accuracy of the temperature drift of the pressure gauge.

In order to realize the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A method for calibrating and correcting pressure gauge temperature drift, comprising the following steps:

S1, the calibration pressure gauge is placed in the oven, and the piston pressure gauge outside the oven is connected through the communication device to complete the calibration of the pressure and strain within the predetermined temperature range, and the calibration pressure and strain of the calibration pressure gauge within the predetermined temperature range are obtained. The corresponding relationship of the standard pressure value;

S2, taking the calibration pressure gauge out of the oven, directly connecting it to the piston pressure gauge, and after standing for a predetermined time, measure a set of data corresponding to the current calibration pressure strain and the current standard pressure value under the current temperature condition;

S3, substituting the current standard pressure value into the corresponding relationship under the current temperature condition to obtain the corrected and calibrated pressure strain amount, performing a differential operation on the corrected and calibrated pressure strain amount and the current calibrated pressure strain amount, and the difference result is used as a communication device transmission error;

S4. Correct all the calibration pressure strains in the corresponding relationship by using the transmission error of the communication device to obtain a calibration pressure strain correction value, and calculate the calibration pressure through the calibration pressure-pressure strain fitting relationship.

Further, in step S1, calibrating the corresponding relationship between the calibrated pressure strain of the pressure gauge and the standard pressure value provided by the piston pressure gauge, and calibrating the corresponding relationship between the intermediate parameter, that is, the pressure strain and the standard pressure value, is more conducive to providing calibration accuracy.

Further, the predetermined temperature range includes the normal use temperature range of the pressure gauge.

Further, in step S2, the predetermined time is more than 1 hour. Standing for more than 1 hour can eliminate the influence of temperature changes after the pressure gauge to be calibrated is taken out of the oven, and ensure that the calibration process of the pressure gauge to be calibrated is carried out under approximately constant temperature conditions.

Further, the corresponding relationship is a polynomial fitting relationship.

Further, in step S1, the calibration pressure strain data is read once at intervals of 5 MPa for the standard pressure value.

Further, at intervals of 1°C, measure the corresponding relationship between the calibration pressure strain and the standard pressure value.

Further, the calibration pressure-pressure strain fitting relationship in step S4 is polynomial fitting.

Preferably, the calibration pressure-pressure strain volume fitting polynomial adopts the fitting polynomial of the corresponding relationship in step S1.

Compared with prior art, the beneficial effect of the present invention:

The present invention measures the calibration result of the piston pressure gauge by taking the pressure gauge to be calibrated out of the oven, and then calculates the difference between the calibration result of the oven at the same temperature and the calibration result of the piston pressure gauge to be directly connected to the pressure gauge to be calibrated to obtain the communication device. transfer error, and then use the transfer error to correct the oven calibration results under all temperature conditions to improve the temperature drift calibration accuracy of the pressure gauge. The temperature drift calibration and correction method provided by the invention does not introduce additional equipment, and the method of optimizing the calibration process improves the temperature drift calibration progress of the pressure gauge, and has the beneficial effects of low use cost, strong practicability, and easy use.

Description of drawings:

Fig. 1 is a flowchart of a method for calibrating and correcting pressure gauge temperature drift in the present invention.

detailed description

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

Example 1

In order to realize the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A method for calibrating and correcting pressure gauge temperature drift, comprising the following steps:

S1, the calibration pressure gauge is placed in the oven, and the piston pressure gauge outside the oven is connected through the communication device to complete the calibration of the pressure and strain within the predetermined temperature range, and the calibration pressure and strain of the calibration pressure gauge within the predetermined temperature range are obtained. The corresponding relationship of the standard pressure value;

S2, taking the calibration pressure gauge out of the oven, directly connecting it to the piston pressure gauge, and after standing for a predetermined time, measure a set of data corresponding to the current calibration pressure strain and the current standard pressure value under the current temperature condition;

S3, substituting the current standard pressure value into the corresponding relationship under the current temperature condition to obtain the corrected and calibrated pressure strain amount, performing a differential operation on the corrected and calibrated pressure strain amount and the current calibrated pressure strain amount, and the difference result is used as a communication device transmission error;

S4. Correct all the calibration pressure strains in the corresponding relationship by using the transmission error of the communication device to obtain a calibration pressure strain correction value, and calculate the calibration pressure through the calibration pressure-pressure strain fitting relationship.

Further, in step S1, calibrating the corresponding relationship between the calibrated pressure strain of the pressure gauge and the standard pressure value provided by the piston pressure gauge, and calibrating the corresponding relationship between the intermediate parameter, that is, the pressure strain and the standard pressure value, is more conducive to providing calibration accuracy.

Further, the predetermined temperature range includes the normal use temperature range of the pressure gauge.

Further, in step S2, the predetermined time is more than 1 hour. Standing for more than 1 hour can eliminate the influence of temperature changes after the pressure gauge to be calibrated is taken out of the oven, and ensure that the calibration process of the pressure gauge to be calibrated is carried out under approximately constant temperature conditions.

Further, the corresponding relationship is a polynomial fitting relationship.

Further, in step S1, the calibration pressure strain data is read once at intervals of 5 MPa for the standard pressure value.

Further, at intervals of 1°C, measure the corresponding relationship between the calibration pressure strain and the standard pressure value.

Further, the calibration pressure-pressure strain fitting relationship in step S4 is polynomial fitting.

Preferably, the calibration pressure-pressure strain volume fitting polynomial adopts the fitting polynomial of the corresponding relationship in step S1.

Table 1 is the temperature drift calibration result table of the original pressure gauge under the condition of 50°C, and Table 2 is the temperature drift calibration result table of the pressure gauge provided by the present invention under the condition of 50°C, and the accuracy calculation formula in the table is: accuracy=(measured value-true value )×100/true value. It can be seen from Table 1 and Table 2 that the pressure gauge temperature drift calibration and correction method provided by the present invention significantly improves the pressure gauge temperature drift correction accuracy.

Table 1 Temperature drift calibration results of the original pressure gauge at 50°C

Table 2 The temperature drift calibration result table of the pressure gauge provided by the present invention under the condition of 50°C

Claims (8)

1. bearing calibration is demarcated in a kind of pressure gauge temperature drift, it is characterised in that comprised the following steps：

S1, nominal pressure meter is placed in baking oven, and the piston manometer connected by communication apparatus outside baking oven completes predetermined temperature model Pressure-strain amount in enclosing is demarcated, and obtains nominal pressure meter nominal pressure dependent variable and piston pressure in the predetermined temperature range The reference pressure value corresponding relation for providing is provided；

S2, nominal pressure meter is taken out from baking oven, is directly connected with piston manometer, after standing the scheduled time, in current temperature One group of current nominal pressure dependent variable and current normal pressure value corresponding data are determined under the conditions of degree；

S3, the corresponding relation under the conditions of Current Temperatures is substituted into by current normal pressure value, obtains correction nominal pressure strain Amount, calculus of differences is made by the correction nominal pressure dependent variable and the current nominal pressure dependent variable, and difference result is used as even Exchange device transmission error；

S4, is corrected with the communication apparatus transmission error to all nominal pressure dependent variables in the corresponding relation, is obtained Nominal pressure dependent variable corrected value, nominal pressure is calculated by nominal pressure-nominal pressure dependent variable fit correlation.

2. demarcation bearing calibration according to claim 1, it is characterised in that the predetermined temperature range is including pressure gauge just Normal temperature in use scope.

3. demarcation bearing calibration according to claim 2, it is characterised in that in step S2, the scheduled time is 1 hour More than.

4. demarcation bearing calibration according to claim 3, it is characterised in that the corresponding relation is closed for fitting of a polynomial System.

5. demarcation bearing calibration according to claim 4, it is characterised in that in step S1, reference pressure value at interval of 5MPa, reads a nominal pressure dependent variable data.

6. demarcation bearing calibration according to claim 5, it is characterised in that at interval of 1 DEG C, determining a nominal pressure should Variable and reference pressure value corresponding relation.

7. demarcation bearing calibration according to claim 6, it is characterised in that nominal pressure-pressure-strain amount in step S4 Fit correlation is fitting of a polynomial.

8. demarcation bearing calibration according to claim 7, it is characterised in that the nominal pressure-pressure-strain amount fitting Multinomial uses the polynomial fitting of corresponding relation described in step S1.