Ludlum Model 44-9 with minor blemishes

The Ludlum Model 44-9 is a "Pancake" style GM Detector. This detector is sensitive to alpha, beta, and gamma radiation. Its size and shape provide easy handling for surveying or personnel monitoring. The detector is energy dependent, over-responding by a factor of 6 in the 60 keV to 100 kdV range when normalized to ¹³⁷Cs.

● Application: Alpha, Beta, Gamma Survey, Sample Counting
● Detector: GM Pancake
● Active/Open Area (cm²): 15/12, Window (mg/cm²⁾: 1.7 Mica
● Background: 60 cpm, Sensitivity: 3300 cpm/mR/hr
The Ludlum Model 44-9 Alpha Beta Gamma Radiation GM pancake type detector is arguably the most popular radiation detector used throughout the world. This detector is sensitive to alpha, beta and gamma radiation, is enclosed within a rugged metal enclosure, and is conveniently shaped and sized for checking contamination on people and objects. This detector operates between 850 to 1000 volts and is compatible with any Ludlum instrument capable of supplying 900 VDC and an input sensitivity of 30 mV or higher.

Most come with a "MHV" connector.