Used Model 14c with 44-9 pancake G-m probe. Some scratches but good condition with calibration. The Ludlum Model 14C survey meter was designed to meet nuclear medicine requirements. The Model 14C is similar to the Model 3, but with an internal energy compensated G-M detector for high range. It includes an external 44-9 GM pancake G-M probe for general purpose survey of alpha, beta, or gamma detection up to 0-200 mR/hr. This additional internal detector creates fifth high range of 0-2000 mR/hr in addition to the four ranges covered by the external probe. It is used in hosptials, universities, power plants and regulatory facilities. Standard scale is 0-2 mR/hr with five counting ranges: x0.1, x1, x10, x100, and x1000. Two “D” cells provide over 200 hours of operation.

The Model 44-9 GM pancake-type detectoris one of the most popular radiation detectors used throughout the world. This alpha, beta, and gamma radiation detector has a rugged metal housing 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.

14C Meter Specifications:
Ludlum 14C Specifications
Compatible Detectors: G-M, scintillation
Meter Dial:Typically 0 - 2 mR/hr and cpm, BAT TEST (others available )
Multipliers: X0.1, X1, X10, X100, X1000
Linearity: Reading within plus or minus 10% of true value with detector connected
Connector: Series "C" (others available )
Internal Detector: Energy compensated G-M (used with X1000 scale only)
Energy Response: Within plus or minus 15% of true value between 60 keV - 3 MeV (internal detector only )
Threshold: 30 mV plus or minus 10 mV
Audio: Built in unimorph speaker with ON/OFF switch (greater than 60 dB at 2 feet )
Calibration Controls: Accessible from front of instrument (protective cover provided )
High Voltage: 900 volts
Threshold: 30 mV plus or minus 10 mV
Response: Toggle switch for FAST (4 seconds) or SLOW (22 seconds) from 10% to 90% of final reading
Reset: Push-button to zero meter
Power: 2 each "D" cell batteries (housed in sealed compartment that is externally accessible )
Battery Life: Typically greater than 1000 hrs.(battery condition can be checked on meter )
Meter: 2.5" (6.4 cm) arc, 1 mA analog type
Construction: Cast and drawn aluminum with beige polyurethane enamel paint
Temperature Range: (-20° C) to 122° F(50° C)
May be certified for operation from -40° F(-40° C) to 150° F(65° C)
Size: 6.5" (16.5 cm)H X 3.5" (8.9 cm)W X 8.5" (21.6 cm)L
Weight: 3.5 lbs (1.6 kg) including batteries

44-9 Probe Specifications
Indicated Use Alpha, beta, gamma survey; Sample counting
Detector Type Pancake-type, halogen quenched G-M
Window 1.7 ± 0.3 mg/cm2 mica, protected by a stainless steel screen (79% open)
Window Area Active: 15.5 cm2 (2.4 in2)
Open: 12.3 cm2 (1.9 in2)
Efficiency (4π):
14C: 5%
90Sr/90Y: 22%
99Tc: 19%
32P: 32%
239Pu: 15%
99mTc: ≤ 1%
125I: 0.2%
Typical Sensitivity
(137Cs gamma) 3300 cpm per mR/hr
Energy Response Energy dependent (see Energy Response Curve on Graphs tab)
Typical Background
(10 µR/hr field) 60 cpm
Typical Dead Time 80 μs
Operating Voltage 900 Vdc
Connector Series "C" (others available)
Input Sensitivity ≥ -30 mV
Construction Aluminum housing with beige powder-coat finish, stainless steel screen (79% open)
Size (H x W x L) 4.6 x 6.9 x 27.2 cm (1.8 x 2.7 x 10.7 in)
Weight 0.5 kg (1 lb)