What is the difference between a differential pressure transmitter and a pressure transmitter? How to classify
Author: Source: Date: 2021-05-25 17:41:18
How to distinguish between differential pressure transmitter and pressure transmitter
1. Different forms of signal output
The output forms include current output and voltage output, including current output, two-wire three-wire system, four-wire system, two-wire system, and intelligent non-intelligent type, mostly non-intelligent type.
2. Different sensors
Sensors can also be divided into diffused silicon sensors, capacitive sensors, and single silicon sensors, most of which are diffused silicon sensors. In addition, depending on the application, there are non-explosion-proof, explosion-proof, and explosion-proof functions.
3. Different test methods
4. Different display methods
The differential pressure transmitter measures the pressure difference between two gases or liquids, which is a relative quantity; the pressure transmitter measures the pressure of a single gas or liquid, which is an absolute quantity. From the perspective of use, two input nozzles are used to introduce two samples to measure their pressure difference; only one nozzle is used to obtain the pressure difference.
2. Classification skills
1. When measuring the liquid level of the pressure vessel, the differential pressure transmitter can be used to measure the lower limit and the upper line, and their output models can be subtracted. It can also be used to measure the density of the medium without changing the liquid level and pressure in the vessel .
2. From the structure of pressure transmitter and differential pressure transmitter, it can be divided into ordinary type and isolated type. The ordinary measuring diaphragm directly senses the pressure and differential pressure of the medium, and the isolating measuring diaphragm receives the stable liquid such as silicone oil pressure. The diaphragm that is sealed between the diaphragms receives the measured pressure is the outer diaphragm.
3. Isolation transmitter is mainly for special measuring medium. For example, the measuring medium will crystallize after leaving the equipment, while the use of ordinary transmitter needs to remove the medium, which will block the pressure conduit and membrane box chamber and make it unable to work normally. Therefore, the isolation type must be selected. The isolation type is usually composed of flanges, that is, after the flange transmitter is installed on the measured medium, its induction is a part of the equipment wall, so it will not take out the medium, and generally will not cause crystal blockage.