If the temperature is below setpoint, the output will be on longer; if the temperature is too high, the output will be off longer. The third controller type provides proportional with integral and derivative control, or PID.
Noise figure. Noise figure (NF) and noise factor (F) are measures of degradation of the signal-to-noise ratio (SNR), caused by components in a radio-frequency (RF) signal chain. It is a number by which the performance of an amplifier or a radio receiver can be specified, with lower values indicating better performance.
The relationship between sound and noise levels is generally described in terms of a signal-to-noise ratio. With a masking noise level between 35 and 100 dB, the threshold for 100% intelligibility is usually a signal-to-noise ratio of 12 dB. The speech signal ranges from about 200-8000 Hz, while human hearing ranges from about 20-20,000 Hz, so the effects of masking depend on the frequency range of the masking noise.