Answer / sam

Please let us know where you have seen this in a instrument
in the field. The normal standard signal is 4 to 20mA.

Answer / pannu

actually we use 4-20mA:-
1. it is a current signal so it does not have a signal drop
as in case of voltage there is a voltage drop depending upon
the wire resistance.
1. if the output of the instrument is 0% it gives out put as
4mA for 100% it gives 20mA.if line breaks no signal is
there we receive 0mA so that we can blow an alarm for no
signal.

Answer / george mathews

The answer in my knowledge is that if we use a 0 - 20 ma ,
in instrument then we cant distinguish if it is off/ close
stage or the wiring to the instrument is cut off some where
in the connection . Bcos in both the case we will get an
input as 0 ma. But when we us 4 -20 ma here we can say when
the instrument is close and when its wiring is cut off bcos
only then we can get 0ma and 4ma on different condition.

Answer / sreenivasulu

because of getting the accurate results we using 0-20ma in
instrumentation instead of voltage

What happens if the Displacer has fallen or has a hole in it?

1 Answers   CCIE,

---

What are the key features of a Distributed Control System? describing the various layers (sensor through to business system interfaces) as well as the hardware, software and security aspects of the DCS.

0 Answers  

---

hello.my friends.i am an electronics & instrumentation engineer.i want to know Q1.why lugs use in instrumentation cable termination? Q2.if limit switch not working what to do?

2 Answers  

---

How to calibrate H2s Dectector

0 Answers   KOC,

---

what is difference between PLC and DCS?

10 Answers  

---

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?

0 Answers   Essar, Reliance,

---

Sir, I want junior executive, Instrumentation question papaer for IOCL, Plz send to arabinda.ghosh83@gmail.com

0 Answers   IOCL,

---

Why Pressure Transmitter is NOT installed before up-stream of an ORIFICE PLATE? in a flow measurement.

4 Answers   Mecon,

---

calculate the rane of level use of this values, h=3 meter density=0.9 , whats the rang?

2 Answers  

---

how does we do bench calibration of a differential transmitter.

1 Answers  

---

NAME ANY TWO PHOTO CONDUTIVE MATERIALS?

1 Answers   DVC,

---

If we interchange HP and LP tapping in drum level measurement and reverse LRV & URV correspondingly.What is the difference between the normal tapping(HP,LP) and reversed tapping(LP,HP)?

2 Answers  

---