Answer / carl_ellis

I assume "MURCREY" is mercury, the chemical with the symbol Hg.

On-Off temperature thermostat controllers have used a
mercury filled switch for control output.

Mercury filled thermometers have been around for centuries.

But I am unaware of a temperature transmitter filled with
mercury. 2 wire, loop powered industrial temperature
transmitters with a thermocouple input have been available
for decades.

Configuration of the temperature scale corresponding to the
4-20mA output range and sensor type depends on the make and
model of the temperature transmitter. Different methods are
configuration
- with a HART communicator
- with pushbuttons and a local display
- with a software program and serial communications cable
and modem (RS-232 or USB)
- factory configuration

Calibration generally consists of trimming the 4.0 and
20.0mA levels by the same means as configuration, above.

why to use 3 wire at RTD ? what's the reason for common wire ?

4 Answers  

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Paper Details: company -- Hindustan Copper Limited post -- GET 2008 Date -- 03.08.2008 Dept.-- Electronics?Instrumentation Aptitude -- 70 Technical-- 80 Total Time -- 2hr 30min I have listed the question I could able to remember 1. BCD equivalent of 43 2. value of K for stability of a system from a given equation 3. transformer connection for darlington connection 4. damping of balastic galvanometer 5. advantage of chart-pen recorder over CRo 6. CRO - how to change bandwidth 7. questions on CRO construction 8. reverse saturation current of si diode 9. advantage of wire wound resistance over carbon resistance 10. core material for a small coil 11. max fanout-- TTL/ECL/CMOS/MOS 12. component of resistance of monolithic IC 13. functions of capacitors in multivibrators 14. to change a sawtooth signal into a square wave we use-- schmit trigger/ schottkey diode/ zener diode 15. relation b/w á & â in transistor ckt 16. function of SiO2 layer in fabrication 17. 3 questions on ODD MAN OUT

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1)how we calculate the drum level? and how we select the transmitter range?

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