What is a Boxcar or Signal Averager?…
The best method to recover a signal from accompanying noise depends very much on the nature of the signal in question and the required representation of the result. Lock-in Amplifiers are extremely powerful signal recovery instruments if the signal is, or can be made to be, an amplitude modulated AC waveform, where the envelope of the modulation is the required output. However, where this cannot be done, or where the rise/fall time of the signal exceeds the available bandwidth, or where the signal is short lived, other techniques are needed. A Signal Averager samples the applied signal at a regular sampling rate and stores the resulting waveform record. It can repeat this process so that a repetitive input signal can be monitored in exactly the same way on each new cycle. Each record is added to the sum of the previous records so that a continuous summation process takes place. Any asynchronous events (noise) will be reduced in amplitude in relation to the amplitude of the synchronous
