Specifications
8
Autoranging
When radiaon levels increase in some modes over certain preset levels, the Inspector EXP uses autoranging,
automacally changing to the X1000 scale. While in CPM or Timed Count (Total/Timer) mode, whenever X1000
is shown above the numeric display, mulply the displayed reading by 1000 to determine the radiaon level.
mR/hr, µSv/hr, and CPS are not applicable.
Operang in Dose/Rate Modes
Cauon: Be sure there is no obstrucon between the detector window and the source being monitored/
surveyed. Avoid making measurements with the GM window facing the sun, as it could aect your readings.
When the mode switch is set to mR/hr and CPM or µSv/hr and CPS, the numeric display is updated every 3
seconds unless you are using the Timer mode. At low count rates, signicant changes in the radiaon level
displayed can take up to 30 seconds to stabilize. For details, see Autoranging in this chapter.
CPM, CPS, and Total counts are the most direct methods of measurement.
mR/hr and µSv/hr are calculated using a conversion factor opmized for Cesium-137. This mode is less
accurate for radionuclides other than Cs-137, unless you have calibrated the Inspector EXP for the specic
radionuclide you are surveying.
The most immediate indicators of the radiaon level are the audio and count light.
Operang in Timer Mode
When the mode switch is set to Timed Count (Total/Timer), the numeric display is updated every second and
totaling starts.
Taking a Timed Count
The Inspector EXP can give you a total count for a med period from 1 minute to 24 hours. The default seng
is 10 minutes. A med total count is useful for determining the average counts per minute over a longer period
of me. The number of counts detected by the Inspector EXP varies from minute to minute due to the random
nature of radioacvity. When a count is taken over a longer period, the average count per minute is more
accurate.
Taking an average allows you to detect low-level contaminaon or dierences in background radiaon due
to altude or soil mineral content. For example, if one 10-minute average is 1 count per minute higher than
another 10-minute average, the increase is likely due to normal variaon. But over 12 hours, a 1 count per
minute increase over the 12 hour background average may be stascally signicant.
You can end a med count by pressing the SET buon while the remaining me is displayed.
Mode Ranges as they are displayed
CPM 0 to 2,999 CPM > 9,999
X1000
10.000 (10,000) CPM to 350 (230,000)PM
Timed Count (Total/Timer) 0-9,999 counts > 9,999
X1000
10.00 (10,000) to 9999 (9,999,000) counts