Answer / anshul jaiswal

if we use 0-20 mA scale for 0-100%,then 0% will be read in two cases;1)when instrument has any kind of damage problem(not responding case)& 2)for the ground level reading.so we use 4-20mA which shows 4mA for 0%(ground level) & 20mA for 100%(full value) and 0mA shows that instrument has any damage problem.And guyz,in the range of 4-20mA the calibration shows linear characterstic too.

Answer / ramali

current output is 4-20 mA.
Let take a transmitter operating range is 0-100%
in this case, 0% is only 4 mA,100%is 20 mA.
Because the transmitter have no power,then its output is
0mA.That means zero , live zero.
zero means there is no process is done.
live zero is transmitter have no power,etc.,

Answer / p.v.srikumar

because if use 0 -20 mA as 0-100% there is any signal cable
damage or cable open it will show only 0%. if use 4-20mA as
0-100% it will show bad process value(live zero).

Answer / yakin patel

Upper all answer is right but its 4ma not 3,2,1 bcz it is calculting prove. Has calcultion

Answer / girish

this answer which are not exact answer
1. signal is linear
2.no noise
3.current signal will not drop

What is basic of instrumentation

8 Answers  

What is the difference between a double acting and single acting positioner? what type of valves use single acting positioners?

1 Answers   AquaTech, NamPower, Samson Resources,

what is maximum vaccume?

4 Answers  

What is an instrumentation amplifier? How is it better than a differential amplifier when handling outputs from a wheatstone's bridge?

2 Answers   Honeywell,

Do you have reference list?

0 Answers  

Hi all, I am Mohamed from Algeria, I'm a senior Technician qualified in instrumentation. I work in an international petroleum and gas company (SONATRACH: Separation of associated gas from crude oil. Production of condensate, LPG and re-injection of dry gas) within the regulation & Control instrumentation department.I am interested for working in Qatar Petrochemical Company (QAPCO) in Qatar.Now,I am seeking a position, which is an opportunity for me to put my experience to good use and actually participate in running on this company. So, Can anyone help how to contact this company? Thanks Mohamed, mahad8331@gmail.com

1 Answers  

What is the basic principle of vibration measurement by BENTLY NEVADA vibration measurement system? and Why it gives the -ve voltage output?

14 Answers   Ensol, GNFC, Reliance, Siemens,

what is the procedure for auto tune in masoneialn 12300 series displacer type transmitter?

0 Answers  

what about your moleg in pogrees with company

0 Answers   MahaGenco,

we have a s-5 simense plc having op7 .recently on op7 showing error 1.plc not present 2. DB error frequently. can u have any solution . please send me.

0 Answers  

hye SAM acn u send your e mail id, so that i can solve my query through e mail?

0 Answers  

How to consider the flow directions for control valve (Globe) Is the there any easy understanding in order to select the flow directions?

3 Answers