Indicated Use	Low-level, wide-energy gamma detection
Detector Type	NaI(Tl) scintillator, 2.5 cm (1 in) dia. x 2.5 cm (1 in) thick
Efficiency (4π)	¹²⁵I: 7% ⁵⁷Co: 10% ¹³⁷Cs: 3% ⁶⁰Co: 3%
Typical Sensitivity (¹³⁷Cs gamma)	175 cpm per μR/hr
Recommended Energy Range	20 keV to 1.5 MeV
Energy Response	Energy dependent (see Energy Response Curve)
Typical Background (10 µR/hr field)	1800 cpm
Photomultiplier Tube	2.86 cm (1.123 in) diameter, magnetically shielded
Operating Voltage	500 to 1200 V
Temperature Range	-15 to 50 °C (5 to 122 °F) May be certified for -40 to 65 °C (-40 to 150 °F)
Environmental Rating	IP65
Connector	Series "C"
Construction	Aluminum with beige powder coat
Size (D x L)	5.1 x 21 cm (2 x 8.25 in)
Weight	0.5 kg (1 lb)

Option	Description	Part Number
Model 180-1	Sample holder for 5.1 cm (2 in.) max. diameter samples.	47-1675
Model 180-1L	Sample holder with lead shielding for 5.1 cm (2 in.) max. diameter samples.	47-2988
Model 180-24	Sample holder for 5.1 cm (2 in.) max. diameter samples.	47-2631
Detector Collimators	Lead collimators.	Various
Sample Planchets	Set of 500 aluminum or stainless steel sample planchets.	Depends on material
Extension Handle	Adjustable aluminum extension handle that extends from 51 to 76 cm (20 to 30 in.).	4002-1241

Description	Part Number
NaI(Tl) Scintillator	40-5154
1.5 in. PMT, Non-Based with Voltage Divider	4002-510
O-Ring	16-8317