Analysis of Causes for Abnormal Display of Diffused Silicon Pressure Transmitters

　　Abnormal display in diffused silicon pressure transmitters such as CFUEIIIERC1、DG1300-BZ-A-2-25-GZ and other models is usually caused by failure of core sensor components、circuit faults or environmental interference. Diffused silicon sensors measure pressure through resistance changes generated by deformation of the silicon diaphragm，when the displayed value drifts、jumps or shows no response，troubleshooting should be carried out from the following three aspects：　　1. Sensor body failure　　Overload of the diffused silicon chip may cause permanent damage，manifested as zero drift exceeding the ±0.1%FS specified in the BAR-GP1 specification. If medium crystallization blocks the isolation diaphragm，the CS-PT1200V model may show delayed response. Check the medium compatibility mentioned in Chapter 4.2 of the KYB-Z04 manual，acidic substances may corrode the silicone oil filling layer.　　2. Circuit system problems　　If there is poor contact in the 4-20mA output loop of the EDYBT-49 transmitter，the displayed value will fluctuate sharply. Use a multimeter to measure whether the supply voltage of BSCYG9010-1.0 is stable at 24VDC±10%，poor grounding of the signal cable shielding layer will introduce 50Hz power frequency interference.　　3. Impact of environmental factors　　When M5151-00000W-700BG operates outside the range of -40~125℃，the temperature coefficient of the silicon material will cause an additional error of ±0.3%/10℃. A vibration environment may cause cracking of the solder joints of model 8472.78-5717，it is recommended to use an anti-vibration bracket during installation.

Standardized Diagnostic Process for Diffused Silicon Sensors

　　According to the fault tree analysis method in the CEMPX215-GATCA1 technical manual，the following five-step troubleshooting method is recommended：　　Step 1：Basic inspection　　Verify whether the range of the BAR-GP1 pressure transmitter matches the actual operating conditions，and check whether there is leakage at the process connection. For liquid media，ensure that the vent valve of the pressure guide pipe is open.　　Step 2：Zero calibration verification　　Refer to Chapter 7 of the KYB-Z04 manual，and perform zero calibration under atmospheric pressure. If the displayed value of DG1300-BZ-A-2-25-GZ cannot return to zero，the sensor diaphragm may be permanently deformed.　　Step 3：Full-scale test　　Use a pressure calibrator to apply 75%FS pressure to CS-PT1200V，if the reading deviation exceeds 0.25%，recalibration is required. Note that the calibration interval should comply with the 12-month cycle requirement of model 8472.78-5717.　　Step 4：Circuit isolation detection　　Disconnect the signal cable of EDYBT-49，and measure the loop current separately. When 4mA corresponds to 0% range，if there is a deviation of more than 0.5mA，it indicates an abnormality in the transmitter MCU module.　　Step 5：Review of environmental parameters　　Record the ambient temperature and humidity data during operation of BSCYG9010-1.0，and compare them with the allowable range in the M5151-00000W-700BG specification.

Key Points for Calibration and Maintenance of Diffused Silicon Pressure Transmitters

　　1. Selection of calibration equipment　　For calibrating CEMPX215-GATCA1 and other models，a pressure standard of class 0.05 or higher should be selected，and it is recommended to use an intelligent calibrator with temperature compensation function. The HART protocol version of DG1300-BZ-A-2-25-GZ must match the handheld communicator.　　2. Detailed calibration steps　　(1) Perform 5-point calibration on KYB-Z04（0%、25%、50%、75%、100%FS）　　(2) Adjust the Zero and Span potentiometers of 8472.78-5717 until the error between the displayed value and the standard instrument is ≤0.1%　　(3) After saving the parameters，perform 3 cycle tests to verify repeatability　　3. Preventive maintenance recommendations　　• Check the aging condition of the sealing ring of CS-PT1200V every quarter　　• Replace the moisture-proof silica gel of EDYBT-49 every year（replace immediately when the color turns red）　　• Avoid long-term operation of BAR-GP1 above 90% range

Typical Fault Cases and Solutions

Selection and Replacement Recommendations for Diffused Silicon Sensors

　　When models such as EDYBT-49 are discontinued，pay attention to the following when selecting replacements：　　• Range coverage：the 25Bar range of DG1300-BZ-A-2-25-GZ can be replaced with the 30Bar model of CS-PT1200V　　• Accuracy matching：the 0.1 class of BAR-GP1 can be upgraded and replaced with the 0.075 class of CEMPX215-GATCA1　　• Interface compatibility：confirm that the G1/4 thread of KYB-Z04 matches the existing pipeline　　If you need to obtain complete technical parameters for 8472.78-5717 and other models or on-site support，please contact our sensor engineering team，we provide free selection consultation and fault diagnosis services.