Assess your understanding of Climatic Testing

1. A three-term controller is:
   (a) a device which displays temperature, humidity and pressure.
   (b) a controller which provides 3 set points, 3 ramps and 3 dwells in a given period of time.
   (c) a method of compensation for the resistance of the leads in a temperature measuring circuit.
   (d) a mathematical system which provides the most accurate control of a climatic chamber.



2. Fluctuations in climatic chamber temperature readings can be minimised by using:
   (a) high thermal response sensors.
   (b) low thermal response sensors.
   (c) long, small diameter sensors.
   (d) four-wire platinum resistance thermometers.



3. A wet and dry bulb psychrometer is used to measure:
   (a) temperature changes with altitude.
   (b) relative humidity.
   (c) air pressure during an anticyclone.
   (d) saturation vapour pressure.



4. The variation of electrical resistance with temperature for a PRT can be written in the form of:
   (a) a higher order polynomial.
   (b) a linear equation.
   (c) a logarithmic equation.
   (d) a parabolic equation.



5. Using the psychrometric chart below, estimate the relative humidity level in %RH given a dry bulb temperature reading of 25 ^oC. and a wet bulb temperature reading of 20 ^oC.