Answer / s.farhan haider rizvi

becouse we can't get 100% sure our device are working
properly or not working.we know that 0 MA DEAD condition
and 4 MA live dead condition,

Answer / anzal

to know actual zero or dead zero

Answer / harold

4 ma is the live zero

Answer / alok kajla

we use 4ma lowest value because it shows that devide is in working condition and at lowst level. if we take 0ma as starting point then we can't differ the situation that device giving lowest value or device is off condition.

Answer / azhar mottur

o know actual zero or dead zero

Answer / abhishek rathore

4mamp current signal consider as 0% if sensor or wireing fault then signal goes to 0mamp controller or operator understand signal fault mode goes.1,2,3mA not consider because bydeafault 1-3% signal present in the systembut 4mA not goes to signal bydefault .so we are consider 4-20mA signal

Answer / ragu.j

All transmitter are working in 1 to 5volts. So, now we
calculate the V=IR. That means Volt equal to
current*Resistance.
for eg :
calculate to(4ma*250ohms)=1000 milli volt or 1volt
and(20ma*250ohms)=5000 millivolts or 5volts.

Answer / fred good

we use up to 3.9 ma for powering instruments

Answer / urooj

4mA is the leakage current that flows in the circuit even
when the least voltage is appied ..

Answer / s hasini

TO MEASURE THE INSTRUMENTAL ERROR

whats the working principle of level transmeter?

6 Answers  

In my plant I want to mount a steam flow transmitter .Flow nozzel is already mounted in steam line .So how can i know the range to put in flow transmitter?

1 Answers  

why are use only 4 to 20ma. signal.

9 Answers   Otsuka,

PT RTD Range: -200 to 500 degree celsius If I configured in DCS Lower range and Upper range . In face plate it shows red colour due to overa range how was the characteristics look If the temperature is more than operating range. how was the characteristics look . whether its in Resistance vs Temperature curve is Linear or Non linear

0 Answers   MSL, SRAAC,

What is compensation for flow ? Why we use compensation ? What are the factors of different compensation ? We not use then what problems may happen ?

0 Answers  

what is installation and commissioning of (fat & sat) of power plant dcs ? this question keeps in desirable conditions of one company .

0 Answers  

When we will do simulation for I/P?IF WE DO SIMULATION through which way either series or parallel?

1 Answers   TVS,

what is HVAC?

1 Answers  

why twisted pair of wires is used in instrumentation ?

6 Answers   ONGC,

Yokogawa dcs normally where will change 4-20 MA to DC voltage( node or I/o cards?)

1 Answers  

I have a close vessel tank which is under vaccum when in running condition so pl. Provide it's range for dp type tx whose flange to flange distance is 440 mm and density is 1

1 Answers  

how to change measuring units from mmwc to cubm/h in rosemount air flow transmitter with hart communicator fluke 744

0 Answers