Answer / 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.

Answer / mohamed yousuf

fire and gas system is nothing but to detect the toxic,
flamable and combustible gases in the plant and also for
giving the awarness of the hazardous through beacons and
loudspeakers.

Can anybody tell me the exact explanation for Functional calibration?When it should be done on process or on lab? Advanced Thanks

2 Answers  

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How to consider the flow directions for control valve (Globe) Is the there any easy understanding in order to select the flow directions?

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What is the difference between local indicator(flow) and flow indicator?

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What is hp & mp seperator .& what is its working principle ?

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What is the use of temperature compensation?

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what is type of protocol used in instrument field to marshalling cabinet cabel. what is the differenance between bus cabel and instrument cabel?

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wht is loops ? how many loops are there?

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Any body have know try work calculation ???

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what is the difference between impact plate n coriolis type solid flow meters n how they works....n which one is better

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Tell me the field calibration procedure step by step with diagram of temperature transmitter, temperature indicator, flow indicator, level indicator, control valve, thermocouple, pressure indicator (digital & analogue).

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

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what is piezo electric transducer?its principle?

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