FOXBORO P0926GJ high-precision differential pressure transmitter

FOXBORO P0926GJ high-precision differential pressure transmitter

Product Overview

The FOXBORO P0926GJ high-precision differential pressure transmitter is an industrial grade process measurement equipment launched by the Foxboro brand under Schneider Electric, belonging to its high-end process control instrument series. This product is designed specifically for differential pressure measurement requirements in harsh industrial environments. With advanced monocrystalline silicon sensing technology, excellent measurement accuracy, and stable operating performance, it has become a core component for monitoring and controlling parameters such as liquid level, flow rate, and pressure in key industrial fields such as petroleum, chemical, power, and water treatment. As an important supporting instrument for Foxboro I/A series distributed control systems (DCS), P0926GJ has good system compatibility and can achieve seamless integration with mainstream industrial control systems, providing accurate and reliable data support for industrial automation production.

Core Technology and Working Principle

2.1 Core Sensing Technology

FOXBORO P0926GJ adopts a design scheme that combines industry-leading monocrystalline silicon sensor technology with capacitive sensing technology. The core sensor chip adopts MD monocrystalline silicon dual chip architecture. This architecture does not require additional overvoltage protection structures or central diaphragms, making the structure simpler. At the same time, it effectively breaks through the technical bottleneck of the mutual limitation between the static pressure range and differential pressure range of traditional sensors, and successfully solves the problem of accurate measurement in small differential pressure and large static pressure scenarios. Monocrystalline silicon material itself has excellent mechanical stability and temperature characteristics, making the sensor chip have ultra-high overload capacity (unilateral overload can exceed 400 times, such as 6kPa range overvoltage up to 2.4MPa), and extremely low measurement noise and high resolution, laying the core foundation for high-precision measurement of equipment.

In addition, the sensor integrates differential pressure, static pressure, and temperature sensors, which work together to achieve real-time compensation for environmental temperature changes. Due to the integration of temperature sensors and differential pressure sensing units on the same chip, there is no gradient difference when the temperature changes, making compensation more accurate and temperature tracking better, effectively reducing the impact of environmental temperature fluctuations on measurement accuracy.

2.2 Detailed explanation of working principle

The workflow of P0926GJ follows the core logic of "pressure sensing signal conversion amplification output", and the specific process is as follows:

1. Pressure transmission: The differential pressure of the measured medium (liquid, gas, or steam) is transmitted to the internal filling liquid (316L stainless steel silicone oil) through the isolation diaphragm of the transmitter. The filling liquid uniformly conducts the pressure to the surface of the monocrystalline silicon sensor chip in the sealed chamber, avoiding direct contact of the medium with the chip and causing corrosion or damage;

2. Signal conversion: When differential pressure is applied to a single crystal silicon chip, the chip undergoes small elastic deformation, causing a change in the capacitance of the integrated capacitive sensing unit inside. The capacitance change has a strict linear proportional relationship with the applied differential pressure value, achieving the initial conversion of pressure signal to electrical signal;

3. Signal processing and output: The capacitance change signal is converted into a weak voltage signal by an internal adaptation unit, and then amplified and filtered by a high-precision amplifier, finally converted into a 4-20mA standard analog signal output. At the same time, by combining digital communication protocols such as HART, Profibus PA, FF, etc., the device can achieve synchronous transmission of analog and digital signals, which not only meets real-time control requirements but also supports remote parameter configuration and diagnosis.

Detailed performance parameters

3.1 Accuracy and stability parameters

As a high-precision differential pressure transmitter, P0926GJ performs excellently in terms of accuracy and stability, with the following specific parameters:

-Measurement accuracy: ± 0.05% (reference accuracy, based on full range), able to maintain high-precision measurement throughout the full range;

-Repeatability: ± 0.02%, ensuring consistency and reliability of multiple measurement results;

-Long term stability: ± 0.1%/3 years. During long-term continuous operation, the measurement accuracy of the equipment deteriorates slowly, effectively reducing the maintenance cost of frequent calibration;

-Temperature influence: The optimal temperature error is ± 0.04%/10K, which can maintain stable measurement performance over a wide temperature range.

3.2 Pressure and Range Parameters

The equipment provides multiple pressure specifications for different industrial scenarios, with a wide range of adjustable ranges and strong adaptability

-Working pressure: We offer three standard working pressure specifications of 16MPa, 25MPa, and 40MPa, and can choose the appropriate model according to actual working conditions;

-Unidirectional overload pressure: up to 40MPa, with strong impact resistance, can adapt to scenarios with instantaneous pressure fluctuations in working conditions;

-Measurement range: The standard measurement range is 100Pa~40MPa, which can be extended to 60MPa through range expansion, covering the full range measurement requirements from small differential pressure to high differential pressure;

-Range ratio: The adjustable range ratio can reach up to 100:1, and users can flexibly adjust the range according to their actual measurement needs without the need to replace equipment to adapt to different working conditions.

3.3 Environmental and Protection Parameters

P0926GJ adopts a fully sealed structural design, which has excellent environmental adaptability and protective performance, and can cope with the challenges of harsh industrial environments:

-Working temperature range: -40 ° C to+85 ° C, suitable for extreme environmental conditions such as severe cold and high temperature;

-Storage temperature range: -40 ° C to+100 ° C, convenient for transportation and storage in low or high temperature areas;

-Relative humidity: 0~100% (no condensation), can operate stably in high humidity environments;

-Protection level: IP67, with complete dust-proof and short-term immersion (depth not exceeding 1 meter, time not exceeding 30 minutes) protection capability, suitable for industrial sites with high dust and humidity;

-Anti interference capability: It has strong electromagnetic interference (EMI) and radio frequency interference (RFI) protection capabilities, complies with industrial electromagnetic compatibility (EMC) standards, and ensures signal stability in strong electromagnetic environments.

3.4 Power and Communication Parameters

-Power supply voltage: 10-30VDC, some models support 24VDC standard industrial power supply, compatible with mainstream industrial power systems;

-Output signal: Standard 4-20mA analog signal, supporting mainstream industrial communication protocols such as HART, Profibus PA, FF, etc., with a communication speed of up to 115200 bps (HART protocol);

-Display and operation: Built in high-definition LCD display screen and physical operation buttons, supporting multilingual display in Chinese, English and other languages, can display real-time measurement values, range, fault codes and other information, convenient for on-site debugging and parameter setting.

Structural design and material selection

4.1 Overall structural design

P0926GJ adopts a modular structure design, mainly composed of five parts: measurement unit, signal processing unit, display unit, wiring unit, and installation base. Modular design facilitates the disassembly, maintenance, and upgrading of equipment. When a component fails, it can be replaced separately without the need to replace the equipment as a whole, effectively reducing maintenance costs. The device has a compact exterior design, with dimensions suitable for standard industrial installation spaces. The installation base supports various installation methods such as threaded connections and flange connections, and can be flexibly selected according to on-site conditions (such as pipeline installation and wall installation).

4.2 Core Material Selection

To ensure the service life of the equipment under harsh working conditions such as corrosion and high pressure, P0926GJ key components are made of high-quality corrosion-resistant and high-strength materials:

-Isolation membrane: 316L stainless steel, with excellent corrosion resistance and mechanical strength, can withstand the corrosion of most industrial media;

-Filling fluid: High temperature stable silicone oil, with good pressure transmission performance and temperature stability, does not solidify or evaporate within the range of -40 ° C to+85 ° C;

-Shell and cavity: 316L stainless steel welded sealed structure, with precision welding technology used at the welding points to ensure sealing performance, while also possessing strong impact and corrosion resistance;

-Terminal block: Nickel plated copper alloy reduces contact resistance and improves the stability and durability of electrical connections.