TM 1-1500-204-23-7
Table 5-2. Relative Response of Survey Meters
Relative Response
Instrument Effective Energy Key
Instrument
22
32
70
120
170
663(a)
Model No. FSN
Victoreen Model 440
0.94
1.04
1.16
1.18
1.16
1.0
NSN 6665-00-938-6806
Victoreen Model 592B
0.23
0.79
1.14
1.20
1.16
1.0
NSN 6665-00-018-5841
Heat Pipe Corp.
1.06
1.16
1.03
1.0
1.03
0.82
Model VR-1 0
NSN 6665-00-581-0220
With Cap Off
AN/PDR-27
NSN 6135-00-164-8753
External Probe Cap
Off
1.71
3.8
4.27
2.88
1.52
1.0
External Probe Cap
On
-
0.34
1.35
1.94
1.34
1.0
Internal Probe
-
0.01
2.22
2.1
20
1.0
(a)
Note that the 663 key response was obtained from Cs-137 gamma rays, which is commonly used for
calibration in the USAF.
hazard, causing personnel ro receive an unwarranted exposure to ionizing radiation. Personnel should understand the
energy dependence characteristics of the Model 592B survey instrument and should not accept all indicated exposure
rates (meter readings) as being true values.
3 Victoreen Model 440 Instrument. In contrast to the Model 592B survey meter, Table 5-2 indicates
that the Model 440 instrument is nearly energy independent for the range of X-ray energies encountered in industrial
radiography.
(b)
Portable geiger counters. Various portable geiger counters are used to measure levels of radiation.
Radiation exposure measurement with portable survey instruments may be affected by such factor as ambient
temperature, configuration of radiation 5-8 source, (i.e. round, square, rectangular, etc.), isotope source, pressure and
relative humidity, direction of radiation beam, radiation quality (effective energy or radiation spectra) and instrument
susceptibility to Radio Frequency (RF) radiation.
(c)
Pocket dosimeters. The pocket dosimeter, used in conjunction with, but never in lieu of, a film badge or
Thermoluminescent Dosimeter (TLD), is a compact, easy to carry device that indicates an individuals accumulated
exposure to radiation. The dosimeter is about the size and shape of a large fountain pen and shall be worn between the
neck and the waist. The pocket dosimeter, contrary to its name, shall be worn on an outer garment and never be placed
inside a pocket.
5-8
