Model 3

General Purpose Survey Meter

Part Number: 48-1605

Features

Low price
Rugged
4-Range Analog Ratemeter
Supports GM & Scintillation Type Detectors
Greater than 2000 Hour Battery Life

The Model 3 is Ludlum's best selling, general purpose, handheld, analog ratemeter known for accuracy and long-lasting dependability. It comes in a variety of measurement ranges and units to support the external radiation detector selected.

The cast aluminum instrument housing with a separate battery compartment and 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, and battery test, an audio on/off switch, a fast/slow response switch, and a count reset button.

A one meter (39 in.) straight type detector cable with "C" style connector is included in the price of the instrument.

Specifications

Application	Alpha, Beta, and Gamma surveying
Compatible Detectors	GM, Scintillation
Detection Range	Dependent on detector
Linearity	Reading within 10% of true value with detector connected
Meter Dial	0 - 2 mR/hr, or 0 - 500 kcpm, BAT TEST (Meter Faces tab lists other available meter faces)
Meter	6.4 cm (2.5 in.) arc, 1 mA analog type
Controls	Rotary Selector Switch: 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: Zeroes meter Audio Switch: Audio on/off, built-in unimorph speaker, greater than 60 dB at 0.6 meters (2 ft.) Calibration Controls: Accessible from front of instrument (protective cover provided)
High Voltage	Adjustable from 400 to 1500 Vdc
Threshold	Fixed at -30 mV ± 10 mV
Temperature Range	-20 to 50 °C (-4 to 122 °F) May be certified for operation from -40 to 65 °C (-40 to 150 °F)
Power	Two each "D" cell batteries housed in externally accessible sealed compartment
Battery Life	Typically greater than 2000 hours with alkaline batteries (battery condition can be checked on meter)
Construction	Cast and drawn aluminum with beige powder coat
Connector	Series "C" (others available)
Size (H x W x L)	16.5 x 8.9 x 21.6 cm (6.5 x 3.5 x 8.5 in.), including handle
Weight	1.6 kg (3.5 lb), including batteries

Meter Faces

This table lists the most commonly used meter faces. Others are available upon request.

Meter Face	Description	Detectors
202-002	0 - 5k cpm BAT TEST	Any
202-085	0 - 2 mR/hr BAT TEST	Model 44-7
202-666	0 - 50 µR/hr BAT TEST	Model 44-2
202-330	0 - 4.2k cpm 0 - 2 mR/hr BAT TEST	Model 44-7
202-654	0 - 50 µR/hr 0 - 8.5k cpm BAT TEST	Model 44-2 Model 44-9
202-627	0 - 2 mR/hr BAT TEST	Model 44-9
202-084	0 - 2 mR/hr BAT TEST	Model 44-6 Model 44-38
202-608	0 - 6.6 kcpm 0 - 2 mR/hr BAT TEST	Model 44-9 Model 44-9-18 Model 44-40 Model 44-88 Model 44-89 Model 44-94
202-241	0 - 2.4 kcpm 0 - 2 mR/hr BAT TEST	Model 44-6 Model 44-38
202-043	0 - 50 cps BAT TEST	Model 44-2
202-379	0 - 20 µSv/hr BAT TEST	Model 44-6 Model 44-38
202-514	0 - 25 µR/hr BAT TEST	Model 44-2
202-676	0 - 4.2 kcpm 0 - 20 µSv/hr BAT TEST	Model 44-7
202-664	0 - 6.6 kcpm 0 - 20 µSv/hr BAT TEST	Model 44-9

Options

Option	Description	Part Number
Portable Scaler Option	Adds scaler counting capability. Includes digital readout, count time selector switch, and count control button.	4464-114
Overload Indicator Option	Adds Overload indicator with a light.	4464-130
Detector Clips	Stainless steel clip attaches to instrument handle or case facilitating one-handed carrying of instrument and detector.	Depends on detector.
Lighted Handle	Handle with LED to illuminate the instrument display.	4464-154
Shoulder Strap	Adjustable nylon shoulder strap.	4363-413
Headphone Jack	Adds headphone jack to instrument.	4464-464
Stereo/Mono Headphones	Adjustable stereo/mono headphones.	22-9313
Transport & Storage Case - Small	Rugged, dust- and waterproof transport and storage case.	2311062
Plastic Disk Check Sources	General purpose check sources used to check instrument response.	Depends on source material and activity.
Mechanical Check Source Holder	Check source holder with swing-away door that attaches to instrument housing.	4062-166
Stick-On Check Source Holder	Adhesive check source holder that attaches to instrument housing.	4464-473