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
CONTROL VALVE OPERATING IN MANUAL BUT NOT IN MANUAL. WHAT SHOULD BE THE PROBLEM ?
How ejector(or)evactor air pump is working in thermal power plant?
how 3 out of 2 Logic/interlocks works? give brief explanation with help of diagram.
how can leve transmetter calibate in feild .and also put cv and flow plz .....
hello friends, can you please send me the model paper or question paper to be prepared for hpcl examinations????????? You can mail me at rahim_here@yahoo.com waiting for your reply........... help me .. plz.....
How many types of sensor
Why is the orifice tab provided?
when a magnet is heated?
Conversions
hi friends,im an instrumentation and contol engg student,can u hlp me of suggsting barc written question paper,my id is roysuvaranjan@gmail.com, cel no.9563591747
what deference between panel earth and systemearth
how to turbine speed measurement?
What are the types of valves?
How many interlocks at turbine side?
how to calibrate load cell