Anhui Tiankang Group produces a series of instruments and meters, including pressure transmitters, thermistors, thermocouples, bimetallic thermometers, temperature transmitters, pressure gauges, pressure transmitters, magnetic flap level gauges, ultrasonic level gauges, level transmitters, radar level gauges, instrument pipe valves, temperature, pressure, flow, and level field instruments; Cables include: power cables, high-temperature cables, oil resistant cables, anti-corrosion cables, silicone rubber cables, driving cables, rubber sheathed cables, waterproof cables, frequency conversion cables, control cables, computer cables, cross-linked power cables, steel core aluminum stranded wires, flame-retardant cables, heat tracing cables, railway signal cables, fire-resistant cables, marine cables, compensating wires, compensating cables, cable trays and other series of wires and cables.

The difference between capacitive pressure transmitters and diffusion silicon pressure transmitters. This entry lacks an information column and a business card image. Adding relevant content makes the entry more complete and allows for quick upgrades. Come and edit it now! The capacitive transmitter has a variable capacitance sensing component called the 'delta' chamber. This sensor is a closed component. The process pressure and differential pressure are transmitted to the sensing diaphragm through the isolation diaphragm and filled with silicone oil, causing displacement. The capacitance difference between the sensing diaphragm and the two capacitor plates is converted into a two-wire output electrical signal of (4-20) mA by electronic components. The electronic amplification circuit consists of a demodulator, oscillator, oscillation control amplifier, current detector, current control amplifier, current limit controller, reference voltage, voltage regulator, etc. By detecting the capacitance signal through them, the oscillation frequency is controlled and then converted into current output. % b) z* _2 Y t8 z9 ^0 o

Catalog 1 Performance? advantage? Disadvantage 2 Working principle 3 Different performance editing

Advantages 1. Can achieve extremely low pressure 2. Strong overload resistance 3. High precision) H, r! V( F% }+ H

shortcoming

Lack of advantages in high-voltage measurement

High requirements for sensor packaging technology

Working principle editing Working principle 'V2 D @ 7~# E6 X; h1 B J. F

The instrument converts the temperature signal into an electrical signal through a temperature sensor, which is then amplified and filtered by a preamplifier before being sent to the A/D conversion module of the CPU for analog-to-digital conversion. Afterwards, the CPU performs data processing, displays and outputs PWM signals. Side media --->Sensor --->Electronic circuit --->Output signal 8 P $M9 G, u: C/q

The pressure of the measured medium directly acts on the ceramic/diffusion silicon diaphragm of the sensor, causing the diaphragm to produce a small displacement proportional to the medium pressure. Under normal working conditions, the large displacement of the diaphragm is not greater than 0.025 millimeters. After the electronic circuit detects this displacement, it converts it into a standard industrial measurement signal corresponding to this pressure. During overpressure, the diaphragm is directly attached to a sturdy ceramic substrate/diffusion silicon. Due to the gap between the diaphragm and the substrate being only 0.1 millimeters, the large displacement of the diaphragm during overpressure can only be 0.1 millimeters. Therefore, the structure ensures that the diaphragm will not undergo excessive deformation, and the sensor has good stability and high reliability. Main characteristics of diffusion silicon pressure transmitter

-I! _&}, [. S7 @ 4 s * e3 T k 1, high stability - better than 0.1% of full scale per year. ! k; X1 P7 ]' _% ?! ?

2. Small temperature deviation - Due to the elimination of the intermediate liquid in the measuring element, the sensor not only achieves high measurement accuracy, but also Q&a+w5 Y0 S (6 @ 3 s)

3. Good reliability - using large-scale ICs, the circuit has good reliability and strong anti-interference performance.

/ t* x* T3 b4 _9 I- p1 h# p　4、 Wide applicability - The product has multiple models and process connection forms, which can adapt to various media in industrial measurement. 6 O5 E8 k: Q1 M+ X3 _

5. Easy installation and maintenance. The product has a reasonable structure, small size, light weight, and can be installed directly at any position. * x0 O7 V8 m; The disadvantages of S3 #~2g7 @ 7F are:

After falling below 0 ℃, the temperature stability significantly decreases

Cannot withstand dynamic pressure

The membrane is prone to damage

Differential editing diffusion silicon pressure transmitter

In the mid-1990s, Icscnsor, Inc. and Nova Corporation in the United States developed a new type of diffusion silicon pressure sensor using two technologies: silicon stone and silicon wafer Yihe. They also developed a diffusion silicon pressure transmitter with high accuracy, low repeatability, and corrosion resistance. The process pressure is transmitted to the diffusion silicon diaphragm through an isolation diaphragm and sealed silicone oil, while the reference end pressure (atmospheric pressure) acts on the other end of the diaphragm. In this way, the pressure difference on both sides of the diaphragm creates a pressure field, which compresses a part of the diaphragm. The other part is stretched, with two strain gauges in the compression zone and the stretching zone respectively, to sense the changes in resistance caused by pressure and convert the pressure signal into an electrical signal Diffuse silicon is difficult to use normally at low temperatures below zero and high temperatures above 85 ℃, and is not suitable for high pressures above 20MPa. Capacitive film pressure transmitter has a history of more than 20 years since its birth in the 1980s. Due to its high accuracy, corrosion resistance, pollution resistance, and good stability, it is an ideal instrument for detecting low vacuum pressure inside and outside the country. M.K.S Corporation in the United States is the main manufacturer of capacitive pressure transmitters, involved in various fields of civilian industry, and playing a leading role in military industries such as aerospace and nuclear industries. This pressure transmitter is made based on the principle that the elastic film generates pressure change under the action of pressure difference, causing capacitance change. It consists of a detection part and a conversion circuit, as shown in Figure 7-34 The detection section consists of two chambers: a vacuum chamber and a detection chamber. The vacuum chamber is a fully sealed structure. After passing the mass spectrometer leak detection, it is formed by long-term exhaust and then sealing the exhaust pipe. The well is equipped with a gas suppressant to eliminate residual gas and maintain high vacuum for a long time The fixed electrode is located in the vacuum chamber and is led out to the outside of the chamber by the electrode lead wire The detection membrane is placed between the high vacuum chamber and the detection chamber connected to the low vacuum test system. The detection membrane is a movable electrode plate, which forms a flat capacitor with the fixed electrode plate and has a certain capacitance (J.). The low vacuum pressure being tested enters the detection chamber through the detection hole, causing the detection membrane to bend and change its distance from the fixed electrode plate, and the capacitance value also changes accordingly. Different low vacuum pressure values determine different capacitance values. The rear capacitance signal is transmitted to the circuit conversion section, which converts, organizes, amplifies, and outputs a standard voltage or current signal that is proportional to the vacuum pressure. This type of pressure transmitter is used for high-sensitivity differential pressure measurement with stable zero point. Good dynamic response characteristics and strong adaptability, generally suitable for measuring static pressure