Model 133 Series Gamma Detector
Ludlum Measurements, Inc.
Page 1
February 2018
Introduction
The Model 133 series of Geiger-Mueller (GM) gamma survey
detectors can be used with any portable ratemeter, scaler instrument,
or area monitor that provides the appropriate amount of voltage (see
table below) with an input sensitivity of 30
+
10 mV.
Model #
Voltage
needed
Energy
Response
(60 keV-
3 MeV)
Linearity
w/o dead
time
correction
Linearity
w/dead
time
correction
133-2 and
133-2-1
550 Vdc
within 25%
0.1 mR/hr
to 200
mR/hr
0.1 mR/hr
to 1 R/hr
133-3 and
133-3-1
550 Vdc
Within 25% 0.1 mR/hr
to 1 R/hr
0.1 mR/hr
to 5 R/hr
133-4 and
133-4-1
550 Vdc
within 15% 1 mR/hr to
2 R/hr
1 mR/hr to
10 R/hr
133-6 and
133-6-1
550 Vdc
within 15% 4 mR/hr to
6 R/hr
4 mR/hr to
40 R/hr
133-7 and
133-7-1
460 Vdc
within 15%
25 mR/hr
to 30 R/hr
25 mR/hr
to 100 R/hr
