Answer / y.kathirvel

the smoke detector is a thing that detects the smoke by intensity variation of that area under control. if any fire occurs there the light intensity on that area decreases. this can be measured my photo metric method.Photometric measurement is based on photodetectors, devices (of several types) that produce an electric signal when exposed to light. Simple applications of this technology include switching luminaires on and off based on ambient light conditions, and light meters, used to measure the total amount of light incident on a point.its o/p will be in mV.

in the pipe line if the control valve fails to respond to controller action,by what means we can stop the flow in the pipe line ?

9 Answers  

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Explain bernoulli’s theorem.

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sir, i preparing hpcl,ongc,barc,hal exams(instrumentation engg)pls send a placement papers

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why bevelling is done in an orifice ?

4 Answers   ABB,

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suggest a sensor to measure rapidly varying temperature?

1 Answers  

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WHY TEMPERATURE TRANSMITTER USED AS WE CAN CONTROL THROUGH THERMOCOUPLE/RTD

5 Answers   Samsung, Thermax,

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What is the three element? And how it work?

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why we use -ve voltages in vibration prob?

1 Answers  

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What is two wire system and how it work

2 Answers   Bhel, IFFCO,

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what are the on/off valve precaution?

1 Answers   Reliance,

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Q1: Consider part of a control loop, which excludes the transmitter, consisting of a process, a controller and a control valve which may be represented by two dead times of 0.5 min each and three exponential lags of 0.8 min., 1.0 min. and 1.5 min. respectively. We wish to express this system as an overall first order plus dead time (FOPLD) model ie gain, time constant and process dead time. (We will see later that this is often done, to simplify controller tuning). For this exercise, gain is considered to be 1.0. (A) If the transmitter is a flow transmitter whose behaviour can be described by a dead time of 0.2 min. and an exponential lag of 0.5 min. in terms of the overall dead time and overall first order lag how can the system behaviour be approximated ? Overall dead time = Overall time constant = (B) If the transmitter is a temperature transmitter with a temperature sensor in a protecting well whose behaviour can be described by a dead time of 0.7 min. and an exponential lag of 15 min. how can the overall system behaviour be approximated now? Overall dead time = Overall time constant =

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HI, can anybody give details about GAS TREATMENT PLANT CONSTRUCTION,as INSTRUMENTATION ENGINEER what are the responsibilites.what are the instruments mainly instrumentation engineer will deal with

0 Answers   GSM, IOCL,

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