Tested Working Ludlum Model 3 Radiation Survey Meter Geiger Counter w/ 44-7 Probe
Used; see photos for condition. Tested working; see photos for operation. Includes Ludlum Model 3 survey meter with Ludlum 44-7 probe and connecting cable. Does not include batteries, radiation sources, or anything else.
The Ludlum Model 3 is a rugged general-purpose handheld analog radiation survey meter designed for use with external GM and scintillation detectors. With the included Ludlum 44-7 probe, this setup is configured for alpha, beta, and gamma surveying using an end-window Geiger-Mueller detector. The Model 3 is Ludlum’s long-running industrial ratemeter platform, featuring a cast aluminum housing, separate battery compartment, metal carry handle, four-decade analog range selector, fast/slow response switch, audio on/off, battery test, and count reset. Ludlum lists battery life as typically greater than 2000 hours with alkaline D cells, and notes that measurement range depends on the specific detector and meter-face configuration installed.
The included Ludlum 44-7 is an end-window GM detector intended for alpha, beta, and gamma survey work and sample counting. Ludlum specifies a 6 cm² active window area, 5 cm² open area, and a thin mica window rated at 2.0 ± 0.3 mg/cm², making this probe useful for contamination surveys, wipe-test checking, general radiation safety work, lab decommissioning support, and other field or bench survey applications where a dependable analog meter/probe combo is preferred. Ludlum lists typical 137Cs gamma sensitivity for the 44-7 at 2100 cpm per mR/hr.
Unit is offered as used and tested working only; no recent calibration is implied. Buyer is responsible for verifying suitability, calibration (if needed), and regulatory compliance for their intended application.
