Ultimate Radiation Detection Kit! Ludlum Model 2241-3 with 4x Probes and Case

Complete Ludlum Radiation Survey Kit

Wide Range Scintillation and GM System

2025 Serviced | Guaranteed | Personal Collection

This listing is for a complete, wide-range Ludlum survey system from my personal collection. It is a versatile and carefully assembled kit intended for serious users who understand the strengths of different detector technologies and want coverage from extremely low "below-background" levels through very high and "dangerous" radiation fields.

This system includes a Ludlum Model 2241-3 ratemeter paired with a broad selection of Ludlum probes, all housed in a custom-fit roller hard case. The combination provides exceptional flexibility for alpha, beta, and gamma detection across a wide dynamic range.

Included Equipment

• 1x Ludlum Model 2241-3 Digital Ratemeter

• 1x Ludlum 44-10 with Large 2"x2" NaI(Tl) Scintillation Detector

• 1x Ludlum 43-65 Alpha Scintillation Detector

• 1x Ludlum 44-89 4x Pancake GM Detector

• 1x Ludlum 133-2 High-Range GM Detector

• Custom roller-style hard case with extendable handle

• Cesium check source shown in photos

• All related documentation as pictured

Detector Overview

Ludlum 44-10 NaI(Tl) Scintillator
A large ( 2"x2") sodium iodide scintillation detector optimized for low-level gamma detection. Its large crystal volume provides excellent sensitivity, making it well suited for environmental surveys, contamination searches, and low-background work where GM detectors are insufficient.

Ludlum 43-65 Alpha Scintillator
A zinc sulfide scintillation probe designed specifically for alpha contamination surveys. This detector offers very high efficiency for alpha particles while maintaining strong rejection of beta and gamma interference when properly adjusted.

Ludlum 44-89 Pancake GM Detector (4x the coverage of the "normal" 44-9)
A 4x thin-window pancake Geiger-Mueller detector capable of detecting alpha, beta, and gamma radiation. This probe is commonly used for surface contamination surveys and general laboratory or field work where wide-area coverage is required.

Ludlum 133-2 High-Range GM Detector
A high-pressure GM probe designed for very high gamma fields. This detector allows measurements extending well into the multiple-R range, making it suitable for applications where standard GM or scintillation probes would saturate.

Meter Configuration and Performance

The Ludlum Model 2241-3 is currently configured for each unique detector for count-based measurements. All scintillation detectors have been properly plateaued, and documentation of detector performance is included. The meter operates smoothly across its full range and has been fully serviced.

Function and sensitivity of all included detectors has been tested and verified to be within specification at time of assessment. 

CPM (Counts Per Minute) is the active display mode. CPS (Counts Per Second) can be enabled at no charge if preferred. Additional configuration options are available upon request.

The meter includes serial output capability and is compatible with Ludlum’s free software for data logging, configuration, and analysis.

Condition and Service

• Fully serviced and verified in 2025

• Guaranteed fully functional with batteries included

• Normal cosmetic wear consistent with careful use

• Guaranteed for one full year (see included paperwork or ask for more details)

This is a well-maintained, professional-grade system that has been taken care of properly. It is ready for immediate use and provides exceptional capability across multiple radiation types and intensity levels.

Additional Information

Fully calibrated systems and alternate configurations are available for rental or purchase. If you have a specific application or configuration in mind, feel free to reach out.

Please review all photos carefully and verify specifications independently if needed. All items shown are included unless otherwise noted.

Same-day shipping when payment clears.
Buyers outside the lower 48 states should contact me prior to purchase to arrange shipping.

Please ask if you have any questions.

This instrument is backed by a 1 year functional guarantee. The warranty covers normal use and operation and does not include damage resulting from abuse, misuse, or mishandling. Ask for more details!