Answer / elham

Hi
No we must not use MOV instead of ESDV. As you know MOV's are working with power but ESDV's are working with Instrument Air (closing and opening) so in the case of power outage we can't close or open MOV but in the case of IA outage we can adjust ESDV on fail safe mode. so ESDV's that should work on emergency cases always are reliable with IA.

Please explain for RS 485 & RS 232 communication

1 Answers   Honeywell,

---

How would you choose differential range?

0 Answers  

---

what is difference between 3 wire and 4 wire RTD sensor?

12 Answers   HTA Instrumentation,

---

Valve positioner and actuators in detail.

0 Answers   MIEPL,

---

what is the difference between plant earth and instrument earth? and what type of cable( cable size ) used for both? and why ?

0 Answers  

---

3. Differentiate between ultrasonic flowmeter and radar type flow meter.

0 Answers  

---

PID controller is used for which type of compensation…… a) lead comp. b) lag com. c) lead lag com.

12 Answers   Engineers India Limited,

---

What are the reliability data ,like failure rate etc,for bently nevada systems & vibration probes.

1 Answers  

---

In dcs panel we are using diff type of modules ?what is module ? what is the use of modules ?diff type of module?

0 Answers  

---

Someone Please tell me what are the Pre-Commissioning activities in a Thermal Power Plant for an instrumentaion Engg.

0 Answers  

---

what is diffrence between analog card and digital card in plc.how analog card work,Please explain in detail.Please send it on abhi_vyas@sify.com

6 Answers  

---

I am applied 100 % pressure on to the air to open control valve,but the valve is not fully closed..and 10-15% is open the valve. how to calibrate the control valve?

3 Answers   OPaL,

---