The SR200 Series Boxcar Averager System is a modular instrumentation platform designed to acquire and analyze fast analog signals. The system consists of a NIM compatible mainframe and modules which can be selected to tailor a system to individual requirements. The SR200 series is flexible enough to handle gate widths from 100 ps to 150 µs, repetition rates up to 50 kHz, and has both analog and digital outputs. With its low-noise inputs and low-drift outputs, the SR200 series is the standard for gated integrators and boxcar averagers.
Gated integrators and boxcar averagers are designed to recover fast, repetitive, analog signals. In a typical application, a time "gate" of predetermined width is precisely positioned relative to an internal or external trigger to coincide with your signal. A gated integrator amplifies and integrates the signal that is present during the time the gate is open, ignoring noise and interference that may be present at other times.
Boxcar Averaging refers to the practice of averaging the output of the gated integrator over many shots of the experiment. Since any signal present during the gate will add linearly, while noise will add in a "random walk" fashion as the square root of the number of shots, averaging N shots will improve the signal-to-noise ratio by a factor of Ã–N.
Analog and Digital Measurements
The SR200 series is designed to work without a computer, allowing you to quickly "tune-up" your experiment, or with a computer, automating complex measurement sequences. Modules like the SR235 Analog Processor perform signal processing functions (e.g., ratioing and background subtraction) without the need for a computer, while the SR245 Computer Interface gives you complete access to boxcar measurements over GPIB or RS-232.