In-Depth Analysis of the Working Principle of Diffused Silicon Wheatstone Bridge Pressure Sensors

As a core component in industrial automation, the YM-1QQ pressure transmitter uses an advanced semiconductor strain principle in its diffused silicon Wheatstone bridge sensor to accurately convert pressure into electrical signals. This article provides an in-depth analysis of its working principle, wiring diagrams, and common fault handling, helping engineers quickly master the key points of selection and calibration, and improve the stability and measurement accuracy of flow control systems.

I. Core Technical Principle of Diffused Silicon Wheatstone Bridge Sensors

The core of the diffused silicon Wheatstone bridge pressure sensor lies in its semiconductor strain gauge technology. When external pressure acts on the sensor diaphragm, the silicon crystal undergoes micro-deformation, causing its resistance value to change regularly. This piezoresistive effect is converted into a millivolt-level voltage signal through a Wheatstone bridge, then amplified and processed by the built-in ASIC chip of the YM-1QQ transmitter, ultimately outputting a standard 4-20mA current signal.

• Strain sensitivity coefficient: as high as 100-150, far exceeding the 2-5 of metal strain gauges
• Temperature compensation: dual-resistor network compensation technology is used, with temperature drift ≤±0.02%FS/℃
• Linearity optimization: laser trimming reduces nonlinear error to ＜±0.1%FS

II. Key Performance Comparison of YM Series Pressure Transmitters

It is particularly worth noting that when used together with the domestic electromagnetic flowmeter KQ-TGF pipeline intelligent electromagnetic flowmeter, the YM series pressure transmitters can build a complete fluid parameter monitoring system. Its 16-bit embedded microprocessor can process multiple sensor signals in real time, meeting the high-precision measurement requirements of scenarios such as petroleum and chemical industries.

III. Typical Wiring Schemes and Signal Processing

The YM-109 pressure transmitter uses a three-wire wiring method: the red wire connects to 24VDC+, the black wire connects to signal output+, and the shielding layer is grounded. Note the following:

1. When the cable length exceeds 50 meters, twisted-pair shielded cable should be used
2. A 0.1μF filter capacitor should be added at the power supply end
3. For HART communication, the terminal resistor should be set to 250Ω

IV. Common Fault Diagnosis and Handling

When the YM-115 pressure transmitter experiences zero-point drift, troubleshooting can be carried out according to the following steps:

• Mechanical inspection: confirm that there is no crystalline attachment on the diaphragm (a common issue in chemical industry scenarios)
• Electrical test: measure whether the bridge resistance is within the range of 3-5kΩ
• Environmental verification: check whether the installation position is affected by mechanical vibration

V. Calibration and Maintenance Specifications

Calibration of the YM-1001 pressure transmitter requires the use of a 0.05-grade standard pressure source and should be carried out according to the JJG882-2019 regulation:

1. Preheat for 30 minutes to stabilize the temperature
2. Evenly select 5 verification points within the full measurement range
3. Measure 3 times in both forward and reverse strokes and take the average value

Recommendations for System Integration Applications

For high-temperature medium measurement in the metallurgical industry, it is recommended to use the PT-507 pressure transmitter together with a ceramic diaphragm assembly. Its measurement range can reach 0-100MPa and it is resistant to temperatures of 400℃. When used in conjunction with flow control equipment, attention should be paid to signal sampling cycle synchronization. It is recommended to use the MODBUS RTU protocol to realize multi-device networking.

Summary and Technical Service Support

As a national high-tech enterprise, Xi'an Shenghongchuang Instrument Co., Ltd. provides full-process technical support ranging from YM-1XH pressure transmitter selection to on-site commissioning. Our engineering team can customize multi-parameter monitoring solutions including pressure, flow, and temperature for you, ensuring the reliable operation of industrial automation systems.

If you need the complete technical manual for YM series pressure transmitters or consultation on system integration solutions, please contact our technical consulting team immediately to obtain professional flow control solutions.