Uses: Pressure transmitters are mainly used to measure the pressure, negative pressure and absolute pressure of gases, liquids and vapors, and then convert them into 4-20mA.DC signal output.
Pressure transmitters include GP type (gauge pressure) and AP type (absolute pressure). The GP and AP models are combined with the intelligent amplifier board to form an intelligent pressure transmitter that can communicate with each other through a HART-compliant hand-held communicator for setting and monitoring. The δ chamber of the GP-type pressure transmitter, one side The measured pressure signal is accepted, and the other side is connected to the atmospheric pressure, so it can be used to measure the gauge pressure or negative pressure. The Δ chamber side of the Ap type absolute pressure transmitter receives the measured absolute pressure signal, and the other side is closed. High vacuum reference chamber that measures the absolute pressure of the exhaust system, distillation column, evaporator and crystallizer!
Principle: Commonly used are capacitor, resonant beam, expanded silicon and other principles!
Capacitive pressure transmitters mainly have room-sensitive components that realize pressure/capacitance conversion and convert capacitors into two-wire 4-20mA electronic circuit boards! When the process pressure is applied from the two sides (or one side) of the measuring chamber to the isolating diaphragm, it is transferred to the central diaphragm of the chamber through the silicone oil filling liquid, and the central diaphragm is an edge-tensioned diaphragm. Under the action of pressure, a corresponding displacement is generated, which changes the differential capacitance! And through the adjustment, oscillation and amplification of the electronic circuit board! Convert to 4-20mA signal output! The output current is proportional to the process pressure!
The purpose and principle of the pressure transmitter