Interested to Buy Any Domain ? << Click Here >> for more details...
d/p flow transmitter LP side give to pressure.what you
geting out put ? how you get(ma)?
- 6 Answers
- 13709 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
What is difference between “Fault Tolerant” & “Fault avoidance” PLC? Application where these system s are used?
How can measure flow in oil line?which type of transmitter is generally used?
How to calibrate Toxic gas detector?
I am using 971 Enraf radar level transmitter for LPG tanks ,the tank side indicator gives the error code 999999999FL can any body give me any diagnostic for this issue?
What is the purpose of LO Overhead tank in turbines.
Explain the working of rota meter.
Linear amplifier.
Why do we have earthing cable in branch cable and shield in the same cable?
hye SAM acn u send your e mail id, so that i can solve my query through e mail?
Can please tell mi about SIOS, PRM, SERVER, and what is the diference between PIN LAN, PCS LAN,APC Server, and please send the Doc if possible for referance,mail id patil_amit17@yahoo.com
what is the importance of CV in the control valves? how it is calculated?
How do you identify an orifice in the pipeline?
why we should maintain neutral earth voltage below 1V while calibration? why cant it be 1.2V or 2V
How to calibration a control valve?
Differentiate between ultrasonic flowmeter and radar type flow meter
