AP131 Pressure Transmitter Calibration Guide: Professional Engineers Share 3 Practical Tips

AP131 pressure transmitter calibration is a key step in ensuring industrial measurement accuracy. In this article, professional engineers from Xi'an Shenghongchuang Instrumentation Co., Ltd. share 3 calibration tips for diffused silicon pressure sensors, covering general methods for transmitters in the KL316, PA1000, and other series, helping operators quickly master the core points.

I. Preparation Before Calibration

Before calibrating the AP131 pressure transmitter, thorough preparation must be completed. First, ensure that the working environment meets the requirements: temperature controlled at 20±5℃, and relative humidity not exceeding 60%. Second, prepare a standard pressure source with an accuracy at least one grade higher than that of the transmitter being calibrated. For diffused silicon liquid and gas pressure sensors, it is recommended to use a standard instrument with Class 0.05 accuracy or higher.

Check the appearance and connection parts of the transmitter:

• Confirm that the pressure port has no leakage
• Check whether the cable connections are secure
• Ensure that the power supply voltage is stable at 24VDC±5%

Special reminder: for precision instruments such as domestic flush diaphragm pressure transmitter FST800-702 sanitary pressure sensor, preheat with power on for at least 30 minutes before calibration to achieve the best working condition.

II. Zero Point and Full-Scale Calibration Tips

Zero point calibration is the basic part of pressure transmitter calibration. For the AP131 model, it is recommended to use the following steps:

1. Under no-pressure conditions, measure the output current, which should be 4mA (two-wire system)
2. If there is any deviation, adjust it through the zero adjustment potentiometer
3. After adjustment, wait 5 minutes and observe the zero point stability

Special attention is required for full-scale calibration:

For models such as the KL-KL316 pressure transmitter with alarm control functions, it is also necessary to simultaneously check whether the alarm point settings are accurate during calibration.

III. Temperature Compensation and Long-Term Stability Verification

The temperature characteristics of diffused silicon sensors significantly affect measurement accuracy. Professional calibration should include a temperature compensation step:

• Select at least 3 temperature points within the 0-70℃ range
• Calibrate after each temperature point has stabilized for 30 minutes
• Record the temperature drift coefficient, which should be ≤±0.05%FS/℃

For long-term stability verification, it is recommended to use an accelerated aging method:

1. Operate continuously for 72 hours and record data once every 8 hours
2. Calculate zero drift and full-scale drift
3. Annual stability should be better than ±0.2%FS

For products such as the PA-PA1000 pressure transmitter with remote transmission signals, the stability of signal transmission must also be verified.

IV. Post-Calibration Acceptance and Document Management

After calibration is completed, strict acceptance must be carried out:

• Repeatability test: 5 consecutive pressurization/depressurization cycles
• Hysteresis test: forward and reverse stroke deviation not exceeding 0.1%
• Linearity check: calculated using the least squares method

It is recommended to establish complete calibration records, including:

For equipment such as the TXY-TXY801 pressure transmitter used in special application scenarios, specific operating condition parameters must also be recorded.

V. Summary and Recommendations

Through the above 3 core tips, the calibration accuracy of the AP131 pressure transmitter can be ensured. Special reminder:

• The recommended regular calibration interval should not exceed 12 months
• Under harsh environments, it should be shortened to 6 months
• Choose the original manufacturer or a certified institution for calibration

Xi'an Shenghongchuang Instrumentation Co., Ltd. provides calibration services for a full range of pressure transmitters, including various models such as DT-131 and NPT-NPT100. Our professional technical team can provide you with customized solutions.

If you would like to learn more about domestic flush diaphragm pressure transmitter FST800-702 sanitary pressure sensor or professional support for other flow control equipment, please contact our engineering team immediately.