Answer / carl_ellis

1-5Vdc is not a standard, it is a widely used convention for 4-20mA current loops.

A 250 ohm resistor drops a 1-5 Vdc voltage proportional to the 4-20mA current.

DCS analog inputs historically used 250 ohms for 4-20mA analog input resistance and over time that value has become quite common.

But I have seen 1 ohm, 4.7 ohms, 10 ohms, 12 ohms, 24.9 ohms, 50 ohms, 62.5 ohms, and 100 ohm resistances for 4-20mA current input.

if we open the inlet of an air regulator ,how it will affect the out put of regulator? (out put of regulator is using to operate an on-off valve.it is an air to open valve,and valve is in open position.my doubt is air regulator will hold the valve in open or not,if there is no consumption or leak in regulator out put side ,we only loose the input pressure.)

4 Answers   Asian Paints,

---

what are the pinciples & units of flow, level, temperature, pressure, quality.

1 Answers  

---

what is meaning of static pressure

4 Answers   Ambuja,

---

Need Intergraph softwares like SPI(INTOOLS),sp3d,PV ELITE, SP P&ID. CONTACT : logu.2211@gmail.com (8867825756)

0 Answers   GE,

---

what is burner management system?

2 Answers   Alstom,

---

what is insdustrial vibration.who it works. give atleast 2 types of insdustrial vibration

0 Answers  

---

CAN YOU USE MOVING COIL METER FOR MEASURING A.C?

2 Answers   DVC,

---

What is linearity of RTD over 0 to 200 degC?

1 Answers   Honeywell,

---

What is difference between loop and zone ?

5 Answers   Adgas, Bilt,

---

How to calibrate level transmitter with use of HART?

0 Answers   Samsung,

---

State 5 different method of level measurements.

3 Answers   SRACO,

---

Difference between 2-Valve Manifolds, 3-Valve Manifolds and 5-Valve Manifolds 3 with diagram

0 Answers   Acire Systems,

---