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.