ORTEC Detective-DX-100T, Руководство пользователя

Страница: 69 / 114

931040P / 1014 5. ADVANCED SETUP
59
Figure 60. Auto-Calibration in
Progress.
5.2.1.2. Auto-Calibration
!
During auto-calibration, the screen displays the
time remaining to completion of the calibration,
as shown in Fig. 60. This number is the real time
for the calibration spectrum acquisition and is
based on the peak count rate. Auto-calibration
will not succeed until the calibration peak passes
the quality test.
!
If the unit does not detect the correct calibration
source, it waits for approximately for 2 minutes,
then posts an error message. Tap Back to return
to the Survey Mode. You can either use the exist-
ing calibration or perform a manual calibration.
The unit will auto-calibrate at the next scheduled
interval.
!
To interrupt auto-calibration, tap the Abort but-
ton, then Back to return to Survey Mode. When
you return the Detective-EX to the auto-calibration function, calibration will immediately
restart from the beginning. The unit will continue trying to calibrate until the calibration
peak passes the quality test.
!
If you disconnect the instrument from the external power source during auto-calibration,
the routine will attempt to run to completion. Tap on the Abort button to interrupt auto-
calibration, then Back to return to Survey Mode. When the unit is reconnected to external
power, auto-calibration will start at the next scheduled interval.
5.2.2. Background Settings
Use this screen to pre-configure the minimum accept-able background radiation measurement
time for the Background command (Section 5.1.4). The instrument requires periodic measure-
ment of a site’s background radiation to reduce false alarms on
40
K and other naturally occurring
radioisotopes from building materials such as concrete. The background file is saved on the
computer in
\Program Files\DetectiveEX
. It is stored as an ORTEC
.CHN
spectrum file named
background.chn
, and is overwritten each time the background is updated. Ideally, a new back-
ground measurement should be made whenever the Detective-EX is moved to a new site. In
addition, a new background is required as the final step of calibration.
The minimum acceptable data collection time for the background measurement is set on the Bkg
Settings screen, shown in Fig. 61.