The Ludlum Model 2220 Portable Scaler/Ratemeter is a self contained counting instrument designed for operation with scintillation, proportional, or GM Detectors. The unit has a voltage-sensitive preamplifier, linear amplifier, electronic timer and detector HV power supply. It is a single channel analyzer for use in gamma spectrum analysis. The analyzer can be switched off to allow for measuring a wide spectrum. Threshold, window, and HV controls are available. It has analog and digital displays.
This unit is similar to the Model 2221 and provides a less expensive alternative to that meter ($750 vs $1250).