Differential pressure transmitter output
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This post was last edited by jych on 2011-12-24 at 19:37. Does a differential pressure transmitter output a flow signal or a differential pressure signal? (I am using an EJA.) Why doesn’t a differential pressure transmitter output a flow signal when used to measure flow? Are there any additional conditions required?
Of course, a differential pressure transmitter outputs a pressure signal itself. Differential pressure transmitters are used in differential pressure flowmeters, and it is only after square root calculation and pressure compensation by the flow integrator that the flow signal is generated.
The output is a current signal. The output of taking the square root within the table is the current signal after taking the square root of the differential pressure ； The output of the DCS square root function is the current signal corresponding to the differential pressure. The specific flow rate corresponding to the current signal depends on how your range setting is configured.
A differential pressure transmitter itself outputs a differential pressure signal. Depending on the application, different display signals are converted in the control room. When measuring liquid level, the height is calculated using the formula H=P/ρg; when measuring flow rate, the formula is too complex……As for measuring differential pressure, there’s no need to use any formulas
The differential pressure transmitter outputs a current signal corresponding to the differential pressure range; if it is an intelligent transmitter, square root output can also be set directly through the menu. In any case, what is output is the differential pressure value. The flow rate value must be displayed by the secondary meter flow integrator, which calculates it based on a formula. It is the signal output by the flow integrator that constitutes the flow signal.
What is measured is the pressure signal, and what is output is an electrical signal
A conventional differential pressure transmitter converts a pressure signal into a displacement signal, which is then transformed into an electrical current signal; in addition, intelligent models also superimpose pulse signals on this electrical current signal.
The output of a differential pressure transmitter should be a current signal; after receiving the differential pressure signal, it uses a square root converter and a translator to generate a current signal corresponding to the flow rate
Well, if it’s for long-distance transmission, current technology isn’t advanced enough; DCS can only receive electrical signals. It should be that the input is pressure (differential pressure signal); the sensor receives the physical signal, the transmitter converts it into an electrical signal in accordance with relevant standards, and the control system then transforms it into the corresponding flow rate or differential pressure. However, if the instruments are displayed on-site, and considering that they represent the most advanced \"eyes\" and \"brains\" in terms of technology, when the instrument on site is a differential pressure gauge, its output will be the differential pressure; whereas if it is a flow meter, its output will be the flow rate.
The differential pressure transmitter actually outputs a current signal, but this signal is generated by measuring the actual differential pressure using an internal strain gauge bridge; after taking the square root inside the transmitter, a current signal is output； Then this current signal is fed into the DCS to calculate the flow rate; that’s roughly how it works. . . . . . .