Answer Posted / ajith294

Fire and gas system usually as part of a saftey system. the
percentage of Lower Explotion limit shall be dectected by
GAS detector and gives the alarm ,normally 20% is High and
40% is High High alarm.

catalytic bead sensor, semiconductor sensor, infrared point
sensor and ultrasonic sensor are using to detect the gases.

there was no establised standared to difine zero air for
calibration. some procedure says pure nitrogen and some
uses sytetic air. But much more realisitc and practical
using ambient air for zero calibration , when area is
considered to be clean.

for span calibration using 2.5 %Methene (CH4) and balance
nitrogen mixer. 2.5 %Methene (CH4)is equal to the 50 % of
LEL.

What is shielding effect?

2230

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where uses EXe /EXd/Exo/Exn/Exp/Exq/EXia

9898

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what is the process to make control schematic ?

2237

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what is interface level measurement.who can calibrate interface level measurement transmitter online

2500

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Explain PID controller tuning & any one method used for it.

7783

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What is the difference between ff transmitter and non ff transmitter

2431

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If fire would be inside the plant which fire detector is to detected the fire.

1586

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please tell no. & add. of consultancy who recruit me in power plant as instrumen engg. present i m working in power plant as ass.t instrument engg. thanku mahesh 09226562826

2077

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What is frequency factor in massflow meter? When using frequency output?

1846

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What is 1:1 redundancy ?

2371

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what is the responsibility of an instrument commissioning supervisor

3145

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What is the purpose of bypass valve across AS valve.

2095

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what is commisioning procedure,2)what is is the main work in commisioning in the field tx to dcs, plz send me detail

2298

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can we replace a slot sensor (inductive type) with limit switch (potenial free contact / no-nc type).

2018

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what is function of switch, and how is it work, explain with difination

2353

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