The Model 177-56 is a rugged benchtop ratemeter with a dual-detector system, allowing the selection of either alpha or beta readings, and works as an alpha/beta frisking station. The instrument supports GM and scintillation type detectors and displays the count rate on a four-decade, linear readout analog meter. It can be used where line power is available or in portable applications for up to 50 hours using the internal rechargeable battery.
Front-panel controls include power on/off switch, volume control, a four-position range selector switch, fast/slow response switch, and push-buttons for count reset, battery test, and high-voltage test. On the back panel are the power cord connection, a 9-pin type "D" data plug, and calibration controls.