Answer / abhijt n. sonar

Derivative gain is used to take the preventive action in
control. i.e. it gives the corrective action for future
based on the nature of present error. And Derivative action
is used to fast the porcess.
Due to this property of Derivative gain, the process may
become fast and unstable. To avoid this, generally
Derivative gain is kept as minimum as possible i.e. zero.

Answer / kyle condran

derivative works on rate of change of error(slope of error) and assumes that the process will continue changing at that rate and tries to overcompensate for it.

so for fast processes upsets or step changes have high error slopes, sometimes almost infinite or straight up, so the control goes nuts trying to compensate for error. There is usually an option to suppress derivative is for step changes but for fast processes is should be zero.

You will see derivative on laggy slow processes such as some temperature and large volume level loops.

Answer / snehchudasama@gmail.com

yes i m agree with this ans that process is fast.but can anyone tell me why process is fast if i increase the derivative gain?or how can system predicted by considering old values?

where are following valves are applicable to install. can any valve be installed any line. globe valve butterfly valve boll valve gate valve

0 Answers  

---

why we use impulse line of flow transmitter at 45 deg. angle both side of orifice plate.

0 Answers  

---

GIVE THE TEMPERATURE RANGE OF PLATIUM RESISTANCE THERMOMETER.

7 Answers   DVC,

---

how can we calibate ph meter. how can we calibrat conductivimeter how can we calibrat massflowmeter & it s working.

1 Answers  

---

control modes

1 Answers   Vedanta,

---

what is the difference between single and double compression cable gland

3 Answers   Petrofac,

---

If an Instrument has 550 ohm internal resistance and the cable used for that instrument is 0.5 ohm per meter resistance. If the voltage is 12volt.How much length cable can be used? Please tell me its Calculation formula.

5 Answers   MOL,

---

draw a loop drawing of vibration beginning to end

1 Answers  

---

I am new in work for 1 of our project we have some instrument in BOM including Pressure, Temp. and so on, I also noticed some objects like pressure switch process HOOK UP; which I don't know what does "HOOK UP" mean here.

3 Answers  

---

What is Difference between PLC and CNC ?

2 Answers  

---

What is the logic a Transmitter control a Control Valve? How the signal going to the Control valve? What are systems/Panels/cables/signal used to control valve from Transmitter?

3 Answers  

---

What is DCS and PLC scanning time?

5 Answers  

---