Assess your understanding of Climatic Testing

- 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. - 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. - 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. - 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. - Using the psychrometric chart below, estimate the relative humidity level in %RH given a dry bulb temperature reading of 25
^{o}C. and a wet bulb temperature reading of 20^{o}C.