• Several common pressure transmitter faults and solutions Feb 22, 2022
    Common pressure transmitter faults and solutions. The main faults are: 1 When the pressure goes up, the transmitter cannot go up. In this case, you should first check whether the pressure interface is leaking or blocked. If not, check the wiring method. If the wiring is correct, check the power supply. If the power supply is normal, check whether the sensor position has output, or simply pressurize to see the output. Whether there is a change. If there is a change, it proves that the sensor is not damaged. If there is no change, the sensor has been damaged. Other reasons for this may be damage to the instrument, or problems with other parts of the entire system. 2 The output of the pressure transmitter does not change, and the output of the pressure transmitter suddenly changes, and the pressure relief transmitter position cannot go back. The cause of this phenomenon may be caused by the sealing ring of the pressure sensor, which has been encountered several times by our customers. Generally, it is due to the specifications of the sealing ring (too soft or too thick). When the sensor is tightened, the sealing ring is compressed into the pressure port of the sensor and blocks the sensor. When pressurizing, the pressure medium cannot enter, but it suddenly bursts open when the pressure is very high. The sealing ring and the pressure sensor change under pressure. When the pressure decreases again, the sealing ring returns to block the pressure port. The remaining pressure cannot be released, so the sensor position cannot be lowered. The way to troubleshoot this problem is to remove the sensor, check directly whether the position is normal, and if so, replace the sealing ring and try again. 3 The transmitter output signal is unstable The reasons for signal instability are as follows: A. The stress source itself is an unstable pressure B. The instrument or pressure sensor has weak anti-interference ability C. The sensor wiring is not secure D. The sensor itself vibrates heavily E. Sensor failure 4 The transmitter has no output when connected to power Possible reasons are: A. Wrong wiring (check both instruments and sensors) B. Open circuit or short circuit of the wire itself C. The power supply has no output or the power supply does not match D. The meter is damaged or the meter does not match E. Sensor damaged 5. There is a large comparison deviation between the transmitter and the pointer pressure gauge. First, deviations are normal. Second, confirm the normal deviation range. Methods to confirm the normal error range: Calculate the error value of the pressure gauge. For example: the pressure gauge range is 30bar, the accuracy is 1.5%, and the small scale is 0.2bar. The normal error is: 30bar*1.5%+0.2*0.5 (visual error)=0.55 bar 6 Error value of pressure transmitter For example: the pressure sensor range is 20bar, the accuracy is 0.5%, the instrument accuracy is 0.2%, the normal error is: 20bar*0.5%+20bar*0.2%=0.18bar. The possible error range in the overall comparison should be based on equipment with large error values. The error range shall prevail. For the above example, the deviation between the sensor and the transmitter within 0.55bar can be considered normal. If the deviation is very large, an accuracy instrument (at least higher than the pressure gauge and sensor) should be used for reference. 7 The influence of the installation position of the micro-differential pressure transmitter on the position output Since the measurement range of the micro-differential pressure transmitter is very small, the self-weight of the sensing element in the transmitter will affect the output of the micro-differential pressure transmitter. Therefore, the position changes that occur when installing the micro-differential pressure transmitter are normal circumstances. When installing, the axial direction of the pressure sensitive part of the transmitter should be perpendicular to the direction of gravity. If the installation conditions are limited, the transmitter position should be adjusted to the standard value after installation and fixation. Schwahr  Technology Co., Ltd. is driven by innovation and quality, focusing on providing sensors, PLC, HMI, customized power supplies, servo motors, frequency converters, instruments and other automation products and solutions. If you have any questions about pressure sensors, Welcome to ask questions and let’s communicate together.sales@schwahrtechnology.com

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