## Process Control and Instrumentation Which thermocouple can be used to measure a temperature of around 1400°C ?

None of these
Platinum-platinum+rhodium
Copper-constantan
Aluminium-chromel

## Process Control and Instrumentation Find the ultimate gain and frequency for a proportional controller in the case of a process having the transfer function Gp(s) = 1/(4s + 1)(2s + 1)(s + 1).

W = √(7/6), Kc = 46/3
W = 1/√14, Kc = 45/7√14
W = 1, Kc = 13
W = √(7/8), Kc = 45/4

## Process Control and Instrumentation Pick out the most suitable instrument for measuring temperature in the range of-40 to 425°C.

None of these
Mercury thermometer
Bimetallic thermometer

## Process Control and Instrumentation Normal mercury thermometer can be used to measure a temperature of about 300°C. However, its maximum temperature measurement range can be increased upto about 500°C by

Increasing the diameter of the tube
Accounting for the tube expansion
Using steel tube in place of glass tube
Filling nitrogen under pressure in the stem

2/s²
4/s³
2/s³
4/s²

## Process Control and Instrumentation Presence of a small amount of water in the organic systems can be determined by the __________ method.

Polarimetry
Electrical conductivity
Emission spectroscopy
Dielectric constant end loss factor