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

defination of plc? why we use plc? application of plc? advantage of plc?

4 Answers  

---

Explain ratio control system.

1 Answers  

---

can i use capillary type dp transmitter converted to capillary type pressure transmitter. if i removed one side capillary tube its work correctly?

1 Answers  

---

which type of rtd is good for any system,2wire,3wire or 4 wire

9 Answers  

---

What is the reverse action and direct action

2 Answers   Samsung,

---

i want to make project on process control using plc.please give me idea about this.

2 Answers  

---

An atmospheric storage tank has a diameter of 20 m and a height of 8m.It is half-full of liquid with the remainder of the space containing air normally at atmospheric pressure. If the connection to atmosphere is accidentally closed off and 10 cubic m of liquid removed, what happens to the internal pressure of the tank? What are the possible consequences for the tank?

1 Answers  

---

what is the difference between -24 : +24 & 0:24 and where it use?

0 Answers  

---

In which principle Woodward Governor 505 work in power plant? What are the input of Woodward governor 505

1 Answers  

---

Which types of quections asked in interview for FORMULATION PLANT (PHARMA)

0 Answers  

---

How to calculate the Range of level transmitter ?

1 Answers   CPCL, Sejong, SSPL,

---

What is the formula to know the error of weighfeeder after having drop test.

3 Answers  

---