Pressure transmitter diaphragm box issues
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Dear sea friends, does the range of a pressure transducer or differential pressure transducer depend on the diaphragm box? Can the plate be used in combination with diaphragms of any range? Can the range be changed arbitrarily? Also, if I continue to use a pressure transducer with a range of 0-25 BAR, but I don’t have one; I only have one with a range of 0-210 BAR, can that be used? Please give me some advice, thank you
The range of a pressure or differential pressure transmitter depends on the diameter and thickness of the diaphragm inside the capsule; the larger the diameter, the smaller the thickness usually is, and consequently the smaller the range； The same is true in reverse. Using a gauge rated at 21.5 Mpa for 2.5 Mpa should not present any problems; it’s just a bit of a waste and not economical. Modern transmitters have a quite wide range; even when 100% of the range is used in applications requiring only 1%, the accuracy is still maintained.
I forgot to mention that the circuit boards of transmitters are basically universal, serving merely to convert and amplify signals. After replacing the circuit board, be sure to reset its upper and lower range settings.
Reply to 3# newttang: So, do we need to use diaphragms made of different materials to measure pressures in different media? I need to measure high-pressure steam – can I use the same diaphragm box as for measuring ordinary materials? Thank you
The same applies here; it’s a normal situation. When measuring steam, make sure that the pressure guide tube is filled with condensate.
Reply to 5# newttang: Also, when I was reading the manual, I saw that the differential pressure transmitter has exhaust screws and drain screws – what kind of air or liquid are they used to remove? What function is it? I don’t understand. Is there a voltage transformer? Thank you
It’s a plug on the body of the watch. When measuring gases without the need for an isolation fluid, if the gauge is placed below the pressure tap, liquid may accumulate over time and needs to be drained in order to reduce errors caused by the liquid column. When filling with the isolation fluid, it is necessary to open the plug simultaneously while filling in order to release any gas present; this ensures that the diaphragm chamber is completely filled with fluid, thereby reducing errors.
Another important function of the plug is pressure relief. When the gauge is taken out of use, and after the main valve is closed, the pressure of the fluid still remains; in such cases, pressure relief is necessary. Generally, this is achieved by using a vent for pressure release, and if no vent is available, then the plug is used for pressure relief
Reply to 8# newttang: Got it, thanks man!