why we use 4-20 mA for calibration of the instruments.why
we cant use 0-20 mA?
Answer Posted / naveen
Logically Zero milli amps means no current in the circuit .
if we have an initial value to be measured , we cant measure
it as zero milli amps . It means no current in the circuit
or the circuit is open . so we go for the span of 4 to 20 mA
. this is coz we can easily split 4- 20 as multiples of four
(4,8,12,16) which means 0%,25%,50%,75%and 100% respectively.
| Is This Answer Correct ? | 24 Yes | 4 No |
Post New Answer View All Answers
When doing a liquid seal on a differential flow transmitter , most of the time the sealing liquid will be heavier then the process fluid. For wich application will the sealing liquid be lighter than the process fluid if transmitter is mounted below the process line.
describe flow nozzel principle?
Which is your favourite subject & explain any one topic of it.
how to calculate the total flow in square root
Where Can i take a SPI INtools training in Mumbai? In Rolta India Ltd to whom I should approach regarding of SPI INtools Training?
how many maximum enter 2mm Dia solid cylindrical pipe into 8mm Dia hollow cylindrical pipe. give answer with calculation.
How do you identify between actual alarm and false alarm in a Temperature Transmitter in SCADA based Control System
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?
why using negative supply for bentley nevada vibration system ?
what is wave length were using ?
what is function of switch, and how is it work, explain with difination
what would be the minimum flow rate that we can measure on rotameter..?
how to design orifice plate?what is the equation?
Can u tell me the principle of the tc,rtd,level switch,pressure switch ,transmitter(pr flow level temp.),vibration...plz
What are de-saturators?