I would like to ask about the classification of pressure gauges
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Have you seen this document? It mentions that pressure gauges can be of the diaphragm type, flange-mounted transmitter type, or standard transmitter type. The standard transmitter type is generally used for measuring relatively clean fluids such as instrument air and water. In a PID system, there’s a pressure tapping tube, a root valve, and then a PG or PT sensor. However, I’m still not quite clear about the first two types of pressure gauges – the diaphragm type and the flange-mounted transmitter type. I would appreciate some guidance from those who know more about this. O(∩_∩)O Thank you. Pressure, diaphragm pressure gauge, flange-mounted transmitter, standard transmitter/pressure gauge
I can’t understand this classification; I remember having come across a standard according to which pressure gauges should be divided into: pressure gauges, vacuum gauges, and pressure-vacuum gauges. I was completely stunned.
What you are referring to is not the classification of pressure gauges, but rather the types of pressure measuring instruments.
Flanged transmitters are suitable for use in environments with toxic, corrosive, or viscous substances, as the absence of pressure transfer tubes reduces the risk of leaks. Transmitters equipped with flanged capillaries allow for reduced heating requirements; for example, water requires heating when using conventional pressure transfer tubes, but with capillaries it can be used at temperatures down to -20 degrees without any heating needed.
Based on their measurement accuracy, pressure gauges can be divided into precision pressure gauges and general pressure gauges. The measurement accuracy grades of precision pressure gauges are 0.1, 0.16, 0.25, and 0.4 respectively ； The measurement accuracy grades of general pressure gauges are 1.0, 1.6, 2.5, and 4.0 respectively. Gauge pressure meters are classified into general gauge pressure meters, absolute pressure meters, and differential pressure meters, depending on the reference for the pressure they indicate. Ordinary pressure gauges are based on atmospheric pressure ； The gauge pressure meter is based on the zero level of absolute pressure ； A differential pressure gauge measures the difference between two pressures being measured. Gauge pressure meters are classified into vacuum gauges, pressure-vacuum gauges, micro-pressure gauges, low-pressure gauges, medium-pressure gauges, and high-pressure gauges based on their measurement range. Vacuum gauges are used to measure pressure values below atmospheric pressure ； Pressure vacuum gauges are used to measure pressure values that are lower than or higher than atmospheric pressure ； Micro pressure gauges are used to measure pressure values below 60,000 Pa ； The low-pressure gauge is used to measure pressure values from 0 to 6 MPa ； Medium-pressure gauges are used to measure pressures ranging from 10 to 60 MPa ； High-pressure gauges are used to measure pressure values above 100 MPa
Are there other forms of pressure gauges?
Impressive. . . What is the difference between flange-type and diaphragm-type?
I guess my question wasn’t clear enough; I’d like to ask about the types of pressure measuring instruments
A general pressure gauge is a mechanical pressure gauge used to measure the pressure of media such as liquids, vapors, and gases that pose no explosion risk, do not crystallize or solidify, and do not cause corrosion in copper alloys； Diaphragm pressure gauges are suitable for measuring the pressure and negative pressure of various fluid media that are corrosive, viscous, or amorphous and non-solidifying ； Flange-type pressure gauges are suitable for measuring the pressure of media that are corrosive, operate at high temperatures, have high viscosity, tend to crystallize or solidify, or contain solid particles.
How are the latter two usually represented in PID?