why do we use 4-20mA as o/p and why don't use 0-20mA or 5-
21mA?
Answer Posted / ahmed eid
Ohm's law voltage = current * resistance
of the standerd voltage in the dcs from 1 to 5 voltge
and the standerd resistance of loop 250 oums
so
V=I*R
the first in the low signal 1 volt
1(v)=I*250(r) =.004 A
.004*1000 = 4 MA
the sacand in the high signal 5 volt
5(v)=I*250(r) = 020 A
.020*250 = 20 MA
| Is This Answer Correct ? | 19 Yes | 0 No |
Post New Answer View All Answers
hii my name is sujith...i am preparing for HPVL GET 2010... so ,,,pls help me by send any previous questions or material to my site.....(Msujith_12@in.com) thank q
If i have 4 Allen Bradely make RS logix 5000 PLC and for viewing that we are using 4 RS view SCADA for 4 different packages. Now, I will want to view two packages on only one SCADA. Then how i will do it?
why we use the ac supply load cell>?can we use the dc supply load cell?advantages and disadvantage of the ac supply load cell?
Explain about safety integrated level protection? . How it was differ from other protections ?
How to fix back the valve actuator stem
Do you have reference list?
PLEASE PROVIDE SAMPLES OF CHEVRON SKILL TESTS
NSV type probe stands for
how to relay switch sense the fault?
What is the difference between uv and ir scanners? and what is the workig principle of both
what are the documents(Construction point of view for a process plant) submitted by contactor initially entering in to new site for client?
Explain signal isolator
what is 24vdc live and dry supply
Draw a simple circuit for a well head control panel used to protect the well against fire, leak, blockage, ESD, & controls the operation of one downhole & one surface safety valve. Explain the operation and controls
Q1]IF THE RANGE FOR FLOW IS -35 TO 125 WHAT WILL BE THE SPAN FOR ABSOLUTE AND FOR NORMAL? Q2]HOW TO CALIBRATE CAPILLARY TYPE LT? Q3]HOW MANY ERROR CALCULATIONS ARE THERE USED IN PROCESS INDUSTRIES? Q4]HOW TO CALIBRATE TEMPERATURE TRANSMITTER? Q5] HOW TO CALIBRATE LEVEL TROLL AND HOW TO CONNECT? Q6]PLEASE TELL ME THE BASIC FOR INSTRUMENTATION WHICH IS APPLIED FOR CALIBRATION AND FOR ALL? PLEASE MAIL THE ANSWER TO honest_yes@yahoo.in