Working principle

The AO910 series diffusion silicon pressure sensor series is a new generation of measuring components produced using imported chips, carefully designed for structure, signal processing, and assembly, and tested according to national and enterprise standards. The basic principle is to use the piezoresistive effect of semiconductors and micro mechanical processing technology to fabricate a Wheatstone bridge on a specific crystal direction of a single crystal silicon wafer using semiconductor processes such as photolithography and diffusion, forming a sensitive membrane. When subjected to external forces, micro strain is generated, the resistivity changes, and the bridge arm resistance changes (one pair increases and one pair decreases). The excitation voltage signal is output, and after computer temperature compensation, laser resistance adjustment, signal amplification and other processing methods, as well as strict assembly inspection, calibration and other processes, a pressure transmitter with standard output signals is produced.

Characteristics

1. Stable output with high sensitivity

The output of a typical strain gauge sensor is only about 10mv, while the full-scale output of a diffusion silicon sensor is about 100mv. The interference and noise factors have relatively small effects, and the cost of the amplification circuit is correspondingly reduced, greatly improving the resolution. There is no dead zone near zero pressure.

2. High precision and good repeatability

The diffusion silicon piezoresistive pressure sensor realizes pressure sensing, pressure transmission force and electrical conversion through the same component, without intermediate conversion links, pressure hysteresis, mechanical displacement deformation, ensuring minimal repeatability and hysteresis error, good linearity, no creep, stability, reliability, and long service life.

3. Good temperature characteristics

Due to the use of advanced technologies such as laser resistance adjustment and computer compensation, as well as clever control of diffusion concentration, full range temperature drift (sensitivity temperature coefficient) self compensation is achieved. Overcoming the defect of high temperature coefficient in semiconductor chips, the zero position and full temperature drift of the transmitter have reached a high level, expanding the operating temperature range.

4. Suitable for applications in hazardous and explosive fields and locations

The diffusion silicon pressure sensor and transmitter have the characteristics of low current, low voltage, and low power consumption, and belong to the intrinsic safety explosion-proof product. They have obtained the explosion-proof certificate issued by the national safety explosion-proof organization.

5. High reliability and anti-interference performance

Due to the use of stainless steel material and special protective structure, as well as a series of protective measures such as lightning protection, anti-interference, overvoltage, and overcurrent for amplification circuits, the product has improved its reliable sealing, anti-corrosion, and resistance to harsh working environments, making it fully suitable for the needs of general industrial field measurement and control.

Technical parameters

1. Technical indicators

Object of use: liquid, gas, or vapor

Measurement range gauge pressure: 0-5KPa~3.5MPa, sealing gauge pressure: 0-7MPa~100MPa

Absolute pressure: 0-20KPa~35MPa, negative pressure:- 0.1MPa～2MPa

Output 4-20mADC

Power supply 12-36VDC

Load characteristics 4-20mADC two-wire system

Temperature range -40 ℃~+85 ℃

The shell protection is better than IP65

Explosion proof type and explosion-proof type d Ⅱ CT6; The intrinsically safe type IA Ⅱ CT6 should be equipped with an external safety barrier

2. Performance indicators

Comprehensive precision accuracy level: 0.1%, 0.2%

Stability better than ± 0.25% FS/3 years

Temperature impact within the range of -10 ℃ to+60 ℃: variation less than ± 0.1%/10 ℃ (0.1 level)

Change less than ± 0.15%/10 ℃ (0.2 level)

-30 ℃~-10 ℃, 60 ℃~+85 ℃: variation less than ± 0.15%/10 ℃ (0.1 level)

Change less than ± 0.20%/10 ℃ (0.2 level)

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

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

As long as the terminal voltage of the input transmitter is higher than 12V, there will be no load impact.

Location affects installation position but does not affect zero point

3. Structural indicators

Structural material shell: stainless steel or low copper cast aluminum

The contact medium material is related to the type of sensor selected and the sealing method used

Fully welded structure: 316L SS

O-ring sealing structure: nitrile rubber, polytetrafluoroethylene or fluororubber

The process connection standard provides M20 × 1.5 external thread

The electrical connection can be led out from any outlet as needed, and it is recommended to use a φ 10 industrial cable as the lead for sealing The universal cable connector PG16 or M20 × 1.5 can be used for the lead out joint, and the non lead end should be sealed with an end cap.

Structural dimensions

AO910 Industrial Diffusion Silicon Pressure Transmitter

AO910X delicate diffusion silicon pressure transmitter

Hessman connector L ≤ 150

Other lead methods L ≤ 120

AO910Y miniaturized diffusion silicon pressure transmitter

AO910Z sanitary diffused silicon pressure transmitter (plane membrane structure)