Ludlum-Model 177-84 Alpha-Beta Benchtop Counter

The Model 177-84 is a microprocessor based radiation survey instrument used to measure and discriminate low level alpha and beta radiation when used with an alpha-beta scintillation or proportional detector. The instrument has automatic background subtract and automatic background update. It also has an adjustable count timer which can be set from 0 to 120 seconds. An external switch must be connected to the instrument to initiate a count.

The radiation level is displayed on two analog meters. The Alpha meter dial indicates 0 - 1000 cpm on a three-decade log scale. The Beta meter dial indicates 100 - 100,000 cpm on a three-decade log scale. Each channel has its own distinguishable click per event audio tone. Beta events are a low pitch and alpha events are a high pitch. Beta clicks per event can be set at 1 per 1, 10, 100, or 1000. Each channel has its own alarm point which is adjustable from zero to full scale. Alarms are indicated by an audible tone and LEDs.