CAUTION: Do not inject a pulse when the Digilert 100 is turned off. Do
not exceed 5 volts.
2. Plug the cable into the upper jack.
3. Start with the Digilert 100 turned off and the Mode switch set to mR/hr.
Hold down the - button on the end panel while you turn the On/Off/Audio
switch to On. (Don't use the Audio setting.)
The display shows CAL, and the Digilert 100 counts down for 15 seconds,
chirping each second. At the end of the 15 seconds, the Digilert 100
beeps several times.
4. The Digilert 100 collects data for 60 seconds, beeping as it does so, with
CAL and the hourglass indicator flashing. At the end of the 60 seconds, it
beeps several times. The display shows CAL and SET.
5. Use the following table to check the Digilert 100's accuracy. The table
shows appropriate pulse generator count rates to calibrate for Cs137. If
the accuracy is not within desired limits, follow steps 5-7. Note that the
Digilert 100 automatically compensates for lost counts due to GM tube
dead time. Thus, the display reading in CPM mode does not equal the
input frequency. You can display uncompensated counts in CPM mode by
continuously holding down the - (minus) button; the reading now
corresponds to the input frequency.
Pulse Generator
CPM
mR/Hr
μ
Sv/hr CPS
Input (PPM)
11,629
11,994
10
100
205
22,661
23,888
20
200
399
52,600
59,720
50
500
995
78,541
95,552
80
800
1,593
93,993
119,440
100
1,000
1,991
6. 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
automatically calculated from the adjustment you make.
7. The new calibration factor is displayed for several seconds, then the
Digilert 100 beeps and resumes regular operation.
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