``The sensor requires application of a 1 second heating cycle which is
used in connection with a circuit voltage cycle of 1 second. Each
cycle is comprised
by 4.8V being applied to the heater for the first 14ms, followed by 0V pulse for
the remaining 986ms. The Vc cycle consists of 0V applied for 995ms, followed by
5.0V for 5ms. For achieving optimal sensing characteristics, the sensor's signal
should be measured after the midpoint of the 5ms Vc pulse of 5.0V.''
[31]
Figure 3.9 shows this sensor.