Detailed Explanation of the PM320 Pressure Transmitter Wiring Diagram: 3 Key Points to Avoid Wiring Errors

As a key device in industrial automation control, the wiring accuracy of the PM320 pressure transmitter directly affects measurement accuracy and system stability. This article provides a detailed explanation of the PM-PM320 pressure transmitter wiring diagram, with a special analysis of 3 key error-prone points in the wiring process of the diffused silicon Hirschmann pressure sensor, helping technical evaluation personnel avoid common installation mistakes and ensure the equipment delivers optimal performance.

1. Basic Analysis of the Wiring Diagram and Signal Transmission Principle

The PM-PM320 pressure transmitter adopts a two-wire or three-wire wiring method, with the core being a diffused silicon Hirschmann pressure sensor. This sensor converts the pressure signal into an electrical signal through the piezoresistive effect of the silicon crystal, and outputs a standard 4～20mA current signal after internal amplification circuit processing. It should be noted that different models, such as the domestic high-temperature pressure transmitter VP2 diffused silicon pressure sensor, may use different electrical connection methods (such as aviation plugs or DIN connectors), and operation must strictly follow the manual of the corresponding specification model.

Typical wiring errors include:

• Confusing the power supply polarity (for 9～36VDC power supply, the positive and negative poles must be distinguished)
• Signal interference caused by unshielded cables (four-core shielded cables must be grounded)
• Ignoring the influence of ambient temperature on line resistance (line loss must be considered within the working range of -20～+85℃)

2. Analysis of Key Points in Diffused Silicon Sensor Wiring

The accuracy grade (Class 0.25 to Class 1.0) of the diffused silicon Hirschmann pressure sensor places extremely high requirements on wiring workmanship. Taking the PM320 as an example, special attention should be paid to the following during wiring:

For high-precision models similar to the VP2 diffused silicon pressure sensor, it is recommended to use a torque wrench to ensure that the tightness of the electrical connectors is within the range of 0.5～1.2N·m, so as to avoid poor contact affecting the temperature drift index of 0.05％FS/℃.

3. Troubleshooting and System Verification Methods

When typical faults occur in equipment such as the DLT-DLT200 pressure transmitter, the correctness of the wiring can be verified through a three-step method:

1. Continuity test: use a multimeter to measure the loop resistance (the normal value should be 250～750Ω)
2. Signal verification: the no-load output should be 4mA (±0.1mA), corresponding to 20mA at full scale
3. Insulation test: insulation resistance between the power terminal and the housing ≥100MΩ (under 500VDC)

Special reminder: the accuracy grade calibration of models such as SPB-SPB101 must be carried out within the temperature compensation range of 0～70℃, and the zero point should be recalibrated every time the ambient temperature changes by 10℃.

4. Installation Optimization Recommendations for Industrial Scenarios

For different application scenarios such as hydraulic control and building automation, the wiring scheme needs to be adjusted accordingly:

• Petrochemical industry: use a 316 stainless steel housing + armored cable, and the corrosion protection grade must reach IP65
• Constant-pressure water supply system: it is recommended to add a signal isolator to avoid inverter interference
• Turbo-generator unit: a temperature compensation module is required (medium temperature range of -30～+85℃)

Similar to the FDS-S pressure transmitter, the PM320 should be fixed with an M20×1.5 thread in a mechanical vibration environment, and a cable bending radius of ≥5cm should be reserved.

Summary and Professional Recommendations

Correct wiring workmanship can enable the PM-PM320 pressure transmitter to achieve a stability index of ±0.1％FS/year. Technical evaluation personnel should focus on: ① operating according to the specifications of similar models such as YSJ-B1 ② regularly verifying the zero drift of sensors such as CX-203 ③ giving priority to selecting high-precision Class 0.25 models under extreme working conditions.

Xi'an Shenghongchuang Instrument Co., Ltd. reminds: for special-range equipment such as PD-PD50, it is recommended that the first installation and commissioning be completed by professional engineers. If you need customized solutions or technical parameters for high-temperature pressure transmitters, please feel free to contact our technical support team.