Required knowledge for barc 2010 instrumentation paper

Specific conductivity(S/cm) = measured conductivity (s)* electrode cell constant (1/cm)
Siemens (S), also called the mho (1/ohm).
electrode cell constant = (length of the column of liquid between the electrode) / (A is the area of the electrodes)


salt concentration control by measuring conductance of water. more the amount of water higher the conductivity.


Type T copper–constantan thermocouple


Type E Chromel-Constantan thermocouple has the highest sensitivity.


At 100 percent relative humidity, wet bulb temperature is maximum and equal to dry bulb temperature. As there is no cooling due to evaporation. Lower the humidity lower the temperature of wet bulb then dry bulb.
Temperature difference between the dry bulb and wet bulb, depends on the humidity of the air.


Latent Heat of fusion 79.72 (cal/g) or 333.55(kJ/kg)


The specific heat of water is 4.186 kJ/kg °k
Q=M*C*(change in temperature).


The rotameter’s scale is linear.


In silicon diodes up to about 5.6 volts, the Zener effect is the predominant effect and shows a marked negative temperature coefficient. Above 5.6 volts, the avalanche effect becomes predominant and exhibits a positive temperature coefficient. In a 5.6 V diode, the two effects occur together and their temperature coefficients neatly cancel each other out, thus the 5.6 V diode is the component of choice in temperature-critical applications.


Control valve size is either equal to or slightly less then the pipe size.


target flow meter used to measure bi-directional flow, signal polarity indicates direction of flow.