d/p flow transmitter LP side give to pressure.what you
geting out put ? how you get(ma)?
- 6 Answers
- 11901 Views
- ABB, I also Faced
- E-Mail Answers
Answer Posted / carl_ellis
A loop powered transmitter's output can NEVER go to 3.0 mA
or 2.0 mA or 1.5 mA because this range is the electrical
current used to run the transmitter's electronics. A 2 wire
transmitter needs about 3.6 mA just to run its own
electronics. A 2 wire transmitter can only go as low as 0.1
or maybe 0.15mA below the nominal 4.0mA 'zero' to 3.9 mA or
3.85 mA.
But, 4.0 mA can be a negative number. There can be pressure
ranges of
-0.5 bar to - 0.8 bar
-0.5 bar to 0.0 bar or
-0.5 bar to +1.0 bar or
If the high side is left open to the atmosphere and a
pressure applied to the low side, the pressure will be
negative because a DP transmitter subtracts the low side
from the high side.
high side minus low side = pressure
atmosphere minus pressure = negative pressure
0 barg minus 0.5 barg = -0.5 barg
Just because the pressure is negative doesn't mean the
output has to be negative. The 4-20mA range just represents
a pressure range and that range can include a negative
pressures. The 4-20mA is interpreted as a positive or
negative value by the receiver, the
DCS/PLC/controller/indicator.
Carl Ellis
Measure First
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
how to measure oxygen which methods are using?
how many types of viberation transmitter and how to calibrate and where use of vibration transmitter
what is loop1 and loop2 in MTS LT?
what is the field bus calble ? what are diffrences in orang colur cable and black coular calble ?
protection relay watchdog contact operation?
If fire would be inside the plant which fire detector is to detected the fire.
why we should maintain neutral earth voltage below 1V while calibration? why cant it be 1.2V or 2V
What is limitation of the ht.of the displacer of a level trol?
What is zone,loop/fire alarm system?
hi sir yhis is zahid ali i am preparing for the jspl at oct.4.please send me the recently updated sample paper.
Please tell me details about Sox,Nox,SWAS analyser????
Which tank weighing system is better to install (Accuracy point of view) 1) Tank weighing system with 3 load cell or 2) Tank weighing system with 4 Load cell
What materials are used in thermo wells?
What is the use of temperature compensation?
what is controlling card in dcs? how u measure dcs memory?what is bus in dcs?how u know dcs speed n ehternet speed?
