AO910 Diffused Silicon Pressure Transmitter

I. Operating Principle

The AO910 series diffused silicon pressure sensors are all made with imported chips, meticulously designed in structure, signal processing, and assembly. They are produced as the new generation of measuring elements, tested in accordance with national and corporate standards. The basic principle utilizes the piezoresistive effect of semiconductors and micromachining technology, fabricating a Wheatstone bridge on a single crystal silicon wafer with specific crystal orientation using semiconductor processes such as photolithography and diffusion. This forms a sensitive membrane that, when subjected to external force, produces minute strain, causing a change in resistivity. This change in resistivity alters the bridge arm resistances (one pair increases while the other decreases) in response to the applied voltage signal. After processing through computer temperature compensation, laser trimming, signal amplification, and rigorous assembly and calibration procedures, a pressure transmitter with a standard output signal is produced.

Section II: Features

1. Stable output with high sensitivity

Generally, the output of a general variable sensor is around 10mV, whereas the full-scale output of a diffused silicon sensor is about 100mV, with less interference and noise, resulting in lower cost for the amplification circuit and significantly higher resolution. There is no dead zone near zero pressure.

High precision, excellent repeatability

Diffused silicon resistive pressure sensors achieve pressure sensing and the force-to-electric conversion through the same component, without any intermediate conversion steps, no pressure lag, and no mechanical displacement deformation. This ensures extremely low hysteresis and repeatability errors, as well as excellent linearity, no creep, stability, reliability, and a long service life.

3. Excellent thermal properties

Advanced technologies such as laser trimming and computer compensation, along with precise control of diffusion concentration, achieve automatic compensation for full-scale temperature drift (sensitivity temperature coefficient). Overcomes the defect of high temperature coefficient in semiconductor wafers, resulting in a higher standard of zero-point and full-scale temperature drift in the transmitter, expanding the operating temperature range.

4. Suitable for applications in hazardous and explosive areas.

Diffusion silicon pressure sensors, featuring low current, low voltage, and low power consumption, are inherently safe explosion-proof products and have obtained the explosion-proof certificate issued by the national safety explosion-proof institution.

5. High reliability and anti-interference performance

The product, constructed with stainless steel material and a special protective structure, boasts a series of protective measures such as lightning protection, anti-interference, over-voltage, and over-current resistance, enhancing its reliable sealing, corrosion resistance, and ability to withstand harsh working conditions. It is perfectly suited for general industrial field measurement and control requirements.

III. Technical Specifications

1. Technical Specifications

Applicable Objects: Liquids, Gases, or Steam

Measuring Range: Gauge Pressure: 0～5KPa～3.5MPa, Seal Pressure: 0～7MPa～100MPa

Ultimate Pressure: 0～20KPa～35MPa, Negative Pressure: -0.1MPa～2MPa

Output 4-20mADC

Power Supply: 12～36VDC

Load Characteristics 4-20mA two-wire system

Temperature Range: -40℃ to +85℃

Shell Protection Exceeds IP65

Explosion-proof Type: Flameproof Type dⅡCT6; Intrinsically Safe Type iaⅡCT6 with External Safety Barrier

2. Performance Specifications

Overall Accuracy - Accuracy Grade: 0.1%, 0.2%

Stability: Better than ±0.25%FS/3 years

Temperature Influence: Within the range of -10℃ to +60℃, the variation is less than ±0.1%/10℃ (0.1 grade)

Variation less than ±0.15%/10℃ (0.2 grade)

-30°C to -10°C, 60°C to +85°C: Change less than ±0.15%/10°C (0.1 grade)

Variation less than ±0.20%/ 10℃ (0.2 grade)

Vibration Impact: When the vibration frequency is between 20-200Hz in any direction, the variation is less than ±0.02% BFSL

Impact: After a 100G shock in any direction for 11ms, the change is less than ±0.02% BFSL.

Load Impact: There is no load impact as long as the terminal voltage of the transmitter is above 12V.

Location Affects - The installation location does not affect the zero point

3. Structural Indices

Structural Materials: Shell - Stainless steel or low-copper cast aluminum

The material of the contacting medium is related to the type of sensor chosen and the sealing method used.

Full-welded structure: 316L SS

O-ring seal structure: Nitrile rubber, polytetrafluoroethylene, or fluororubber

Process Connections - Standard provides M20x1.5 external threads

Electrical Connections: Can be routed from any outlet as required. It is recommended to use φ10 industrial cables for wiring to ensure sealing. The outlet junctions can be selected from general-purpose cable connectors PG16 or M20×1.5, with the unconnected end sealed with a cap.

Section 4: Structural Dimensions

AO910 Industrial Diffused Silicon Pressure Transmitter

AO910X Compact Diffused Silicon Pressure Transmitter

Hessman connector L≤150

Other wire lead methods L ≤ 120

AO910Y Miniaturized Diffused Silicon Pressure Transmitter

AO910Z Sanitary Type Diffused Silicon Pressure Transmitter (Flat Membrane Structure)