Principles of Pressure Transmitter Application and Techniques for Verification and Verification

The principle and application of ceramic pressure transmitter

No corrosion transfer liquid pressure transmitter, the pressure directly on the front surface of the ceramic diaphragm, produce a slight deformation of the diaphragm, the thick film resistors printed on the back of the ceramic diaphragm, connected into a Wheatstone bridge ( Closed bridge), due to the piezoresistive effect of the piezoresistors, causes the bridge to produce a highly linear voltage proportional to the pressure and a voltage signal proportional to the excitation voltage. The standard signal is calibrated as 2.0 / 3.0 / depending on the pressure range. 3.3 mV/V, etc., compatible with strain gauge sensors. By laser calibration, the sensor has high temperature stability and time stability, temperature compensation sensor built 0 ~ 70 ℃, and the vast majority of media and can be in direct contact.

The principle and application of diffusion silicon pressure transmitter

Measured medium pressure directly on the sensor diaphragm (stainless steel or ceramic), the diaphragm to produce micro-displacement is proportional to the medium pressure, the resistance value of the sensor changes and this change measured with the subject electronic circuit, And convert and output a standard measurement signal corresponding to this pressure.

The principle of capacitive pressure transmitter

Capacitive pressure transmitters are mainly composed of capacitive sensing elements that convert pressure and capacitance , and 4-20mA electronic circuit boards that convert capacitance into two-wire systems. When process pressure is applied from the measuring chamber from both sides (or one side) of the diaphragm, silicone oil filling the center of the diaphragm is transmitted to filling the chamber, a center of the diaphragm is tensioned diaphragm edge, under the effect of pressure, it generates a corresponding displacement that form a differential capacitance change! And through the electronic circuit board adjustment, oscillation and amplification! Convert to 4-20mA signal output! The output current is proportional to the process pressure!

Pressure transmitter verification and verification tips and methods:

First of all, we must select the corresponding pressure source according to the non-ranging and different types of pressure transmitters, and then select the corresponding pressure calibrator or precision digital pressure gauge according to the pressure transmitter being calibrated. The pressure transmitter with smaller range or oil-rejection requirements can choose pressure-type pressure calibration tables. Pressure transmitters with larger range or oil-rejection requirements need to select pressure-type pressure-calibration tables. Larger and no other requirements can be selected hydraulic pressure test stand. The standard meter can select the MY-YBS-WB type digital pressure calibrator, which can be used in one machine and multiple modules, select the appropriate range of pressure module according to the pressure transmitter to be calibrated, or select the MY-YBS-C type. The precision digital pressure gauge is used as an calibrator with an appropriate range.

After selecting the equipment, connect the standard meter with the pressure transmitter and pressure checker and start to suppress. According to the scope of the pressure transmitter, take 5 to 10 points, and then pressurize to the pressure point to be calibrated. Compare the pressure transmitter with the standard table. If there is a deviation, you need to use the communicator or the instrument menu button to adjust the pressure transmitter.

While adjusting the pressure value, the 4-20mA current output from the pressure transmitter needs to be calibrated. When the zero position is reached, the pressure transmitter output signal is 4mA; when the full scale is 1/2, it corresponds to the output. It is 12mA; at full-scale, whether the corresponding output is 20mA.

In this case, the entire calibration process and method of the pressure transmitter is realized. After the entire process is correctly mastered, appropriate equipment can be selected to verify all pressure transmitters that are used for a long time online, so that the measurement reliability can be greatly improved. .