Working Principle of the CPS-C Pressure Transmitter：How Does a Diffused Silicon Sensor Measure Accurately？

In the field of industrial automation，the accuracy and reliability of pressure transmitters directly affect production safety and efficiency。As a representative product using a diffused silicon sensor，the CPS-C series delivers outstanding performance in liquid and gas pressure measurement thanks to its unique working principle。This article will systematically analyze its technical principle and provide professional guidance for the installation and commissioning of common models such as PD50-GB10CM20M4M and FST800211G3451-25B。

1、Core Working Principle of the Diffused Silicon Sensor

The core of a diffused silicon pressure sensor lies in the piezoresistive effect of the silicon wafer。When external pressure acts on the sensor diaphragm，the lattice structure inside the silicon crystal deforms，causing a change in carrier mobility and thereby changing the resistance value。The CPS-C series uses high-purity monocrystalline silicon wafers，and forms a Wheatstone bridge structure through ion implantation technology。Its sensitivity can reach above 2mV/V，far exceeding that of traditional strain-gauge sensors。

Temperature compensation is the key to ensuring accuracy。This series has built-in dual-channel temperature sensors，which correct temperature drift in real time through a dedicated ASIC chip，extending the operating temperature range to -40℃~125℃，with full-scale accuracy stabilized at ±0.25%FS。For example，the HDA4445-A-250-Y00 model can still maintain ±0.1% linearity under high-temperature operating conditions。

In terms of media compatibility，a combination of a 316L stainless steel isolation diaphragm and fluororubber sealing ring is used，enabling measurement of corrosive media such as acid and alkali solutions（within the PH value 2-12 range），saturated steam，etc。For models such as PTG-PTG702，the diaphragm can be optionally made of Hastelloy to handle highly corrosive environments。

2、Technical Comparison of Typical CPS-C Series Models

Note：The STZ2-3 model adopts a special packaging process，and its IP68 protection rating supports long-term operation underwater at 3 meters；while the SAM-K series has passed military-grade vibration testing and is suitable for high-vibration environments such as construction machinery。

3、Practical Guide for Installation and Commissioning

The correct installation method directly affects measurement accuracy。For threaded connection models such as RC-RC301，please note：

1. The installation location should avoid vibration sources and heat radiation areas，and small-range models such as HDA4445-A-100-Y00 are especially sensitive。It is recommended to use a siphon or buffer bend on process pipelines to reduce the impact of pulsation。

2. Selection of sealing gaskets：PTFE gaskets are preferred when measuring gases，and metal spiral-wound gaskets are recommended for liquid media。The G1/2" interface of PD50-GB10CM20M4M must be used with a 16mm thick gasket。

3. Electrical connection：Shielded twisted-pair cable is required for 4-20mA output，and the line resistance must not exceed 600Ω。For systems requiring synchronized monitoring，such as Domestic Weighing Sensor JLET-1 Column Type Tension Sensor for Aggregate Scale in Batching Silos，independent power supply is recommended to avoid signal interference。

4、Key Points for Fault Diagnosis and Maintenance

Common problems and solutions：

• Output signal drift：Check whether there is leakage at the process connection，and the diaphragm assembly of FST800211G3451-25B requires an annual airtightness test

• Abnormal zero point：Confirm whether the drain valve is closed。For the CY-H micro-pressure transmitter，the installation inclination must be controlled within ±1°

• Communication interruption：Verify whether the power supply voltage of PTG-PTG702 is stable within the 12-36VDC range and whether the Modbus address setting is correct

Regular maintenance recommendations：Perform zero calibration every 6 months and use a standard pressure source for full-scale verification。For high-precision models such as STZ2-3，annual inspection in a laboratory environment is recommended。

5、Analysis of Industry Application Scenarios

In the petrochemical industry，the SAM-K transmitter is used for reactor pressure monitoring，and its ±0.05% accuracy can ensure the stability of polymerization reactions。In water conservancy and power systems，the RC-RC301 series，with IP67 protection and lightning-resistant design，is widely used for pipeline network monitoring in water pump stations。

Especially in batching and weighing systems，it is often used together with Domestic Weighing Sensor JLET-1 Column Type Tension Sensor。The former monitors the pressure of the hydraulic system，while the latter measures material weight，jointly building a closed-loop control system。

Summary

The CPS-C pressure transmitter achieves high-precision pressure measurement through a diffused silicon sensor，and each model is differentiated in material，range，and output mode according to the application scenario。Correct installation and regular maintenance are key to ensuring long-term stable operation。If you need the technical manual or installation guidance for a specific model，please contact our engineering and technical team。