Ludlum Measurements, Inc.  Ludlum Model 3

   Radiation Survey Meter




Ludlum Model 3 Radiation Survey Meter●  Alpha, Beta and Gamma Radiation Surveying

 Supports GM and Scintillation Detectors

●  4 Decade Analog Meter

 Greater than 2000 Hour Battery Life

●  Rugged, Low Cost

●  Intrinsically Safe Version Available - Model 3-IS


The Model 3 is Ludlum's best selling, general purpose, handheld analog radiation survey meter known for accuracy and long-lasting dependability. The analog meter comes in a variety of measurement ranges and units to support the external radiation detector selected. The aluminum cast instrument housing with its separate battery compartment and accompanying metal handle offer an industrial robustness and quality that promote long-lasting protection and instrument life. The front-panel controls include a rotary switch for selecting the four-decade range, instrument shut-off, battery test, an audio on/off switch, a fast/slow response switch, and a count reset button. A 39 in. straight type detector cable with "C" style connector is included in the price of the instrument.




Ludlum Model 3 Radiation Survey MeterPART NUMBER: 48-1605

APPLICATION: alpha, beta, and gamma radiation surveying
DETECTION RANGE: dependent on detector


LINEARITY: reading within 10% of true value with detector connected
HIGH VOLTAGE: adjustable from 400-1500 Vdc
THRESHOLD: fixed at 40 mV ± 10 mV

METER FACE: 0-2 mR/hr, or 0-500 kcpm, BAT TEST (others available)
METER: 2.5 in. (6.4 cm) arc, 1 mA analog type, 4 decade


Rotary Selector: switches between instrument off, battery check, ranges: x0.1, x1, x10, x100

Response Switch: toggles between FAST (4 s) or SLOW (22 s) from 10% to 90% of final reading

Reset Pushbutton: to zero meter

Audio Switch: for audio on/off, built-in unimorph speaker, greater than 60 dB at 2 ft (0.6 m)

Calibration Controls: accessible from front of instrument (protective cover provided)

CONSTRUCTION: cast and drawn aluminum with beige powder coat
CONNECTOR: series “C” (others available)

ALARM: No (see Model 3A for version with alarm)
-4 to 122 °F (-20 to 50 °C), may be certified for -40 to 150 °F (-40 to 65 °C)
POWER: two each “D” cell batteries (housed in externally accessible sealed compartment)
typically greater than 2000 hours with alkaline batteries
6.5 x 3.5 x 8.5 in. (16.5 x 8.9 x 21.6 cm) (H x W x L), including handle
WEIGHT: 3.5 lb (1.6 kg), including batteries



 Options & Accessories


Ludlum Lighted Handle

Ludlum Shoulder Strap

Ludlum Overload Indicator

Ludlum Scaler Option

Ludlum Headphones

Lighted Handle

Shoulder Strap

Overload Indicator

Scaler Option



0.25 µCi Cs-137 Radiation Check Source

Ludlum Storm Case




Check Source

Storm Case





 Technical Information


Data Sheet

Product Manual

CE Certificate

Model 3/Model 44-9 Data Sheet

Model 3/Model 44-2 Data Sheet



Training Video


 Ludlum Resources


About Ludlum

Product Catalogs & Price Lists

Standard & Extended Warranty

Software Downloads

Replacement Parts

Repair & Calibration