Radiation Alert Inspector EXP+, User Manual

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10
check when the Inspector
+
is first turned on.
Calibrating Electronically
You can calibrate electronically using a pulse or function generator. Electronic calibration requires a cable with a 2.5 mm
plug, with the tip carrying the signal. Follow these steps:
1. Set the signal height to 3.3 volts and a
positive
pulse width of 85 microseconds.
CAUTION: Do not inject a pulse when the Inspector
+
is turned off.
Do not exceed 5 volts.
2. Turn on the Inspector
+
and set the mode switch to mR/hr
µµ
Sv/hr .
3. Plug the cable into the upper jack.
4. Use the following table to check the Inspector
+
’s accuracy. The table shows appropriate pulse generator count rates
to calibrate for Cs-137. If the accuracy is not within desired limits, follow steps 5-7. Note that the Inspector
+
automatically compensates for lost counts due to GM tube dead time. Thus, the display reading in CPM mode will
not equal the input frequency. You can display uncompensated counts in the CPM mode by continuously holding
down the “-” button. The reading will now correspond to the input frequency.
Pulse Generator CPM mR/Hr
µµ
Sv/hr CPS
Input (PPM)
31,423 33,400 10.00 100.0 557
59,335 66,800 20.00 200.0 1,113
127,043 166,999 50.00 500.0 2,783
177,752 267,200 80.00 800.0 4,453
205,031 334,000 100.0 1,000 over range
5. Turn off the Inspector
+
. Hold down the ”-” button on the end panel and turn on the Inspector
+
. The display shows
CAL , and the Inspector
+
counts down for 15 seconds, chirping each second. At the end of the 15 seconds, the
Inspector
+
beeps.
6. The Inspector
+
collects data for 30 seconds, chirping every 2 seconds, with CAL and the hourglass icon flashing. At
the end of the 30 seconds, it beeps. The display shows CAL , and SET is flashing
7. Press the “+” and “-” buttons to adjust the reading to what it should be. When the reading is correct, press the Set
button.
The new calibration factor is displayed for several seconds, then the In beeps and resumes normal
operation.
Troubleshooting
The In is a highly reliable instrument. If it does not seem to be working properly, look through the following chart
to see if you can identify the problem.
Problem Possible Cause What To Check
Display works, but no counts are
registered defective Geiger tube
or bad cable look through the window to check the mica surface of
the tube; if it is wrinkled or a break is visible, replace it
check EXP cable Connection
Reading is high, but another instrument;
has a normal reading in the same location contamination scan the In (EXP+) with another instrument
replace rubber strips on back of In
Instrument has false high reading moisture circuit board may be wet; dry the instrument in a warm
dry place; if it still has a problem, it requires service
Instrument has false high reading photosensitivity remove from direct sunlight and ultraviolet sources; if
the high count drops, the mica window coating may
have washed off the Geiger tube due to getting wet; the
tube will need to be replaced
Instrument has false high reading continuous discharge replace the Geiger tube
Instrument has false high reading electromagnetic field move the instrument away from possible sources of
electromagnetic or radio frequency radiation
Display is blank no battery, dead
battery, poor battery
connection defective
LCD install a new 9-volt battery if count light and audio work,
the LCD may need to be replaced