Model 702i and 711i
Technical Manual
Section 7
Ludlum Measurements, Inc.
Page 7-5
December 2018
Figure 10 -
Spectrum Search Mode Screen
The
Spectrum
screen is designed for users with a health physics background to see the data collection
and statistics in real time. Certain changes in the spectrum shape, such as that produced by beta
particle interactions, can be interpreted by the trained eye, even when it cannot be identified by the
automated algorithms. This screen provides a dynamic display for this particular set of users.
Audible Search Setting
All of the search modes described above are visually oriented. However, there may be times when
watching the display screen is inconvenient, either because you need both hands free for other
activities, or because you need a more inconspicuous way to monitor for radiation. In addition, the
human ear is surprisingly sensitive to changes in rate, so you may find that you can better tell
whether you are seeing abnormal radioactivity by enabling the audible output.
The
Audible Count Rate
setting in the
Field Settings
menu turns on a click that increases in frequency
along with the input count rate. This sound continues as long as the instrument is collecting data, so
it also gives feedback when you are in menus and other screens that do not show count rate
information
Note:
Enabling the
Audible Count Rate
may noticeably reduce your battery life.
Taking a Background
To ensure accurate results, it is very important to take frequent background spectra in the actual
monitoring location. The background is the point of reference against which readings are measured,
and corrects for ambient radioactivity or background radiation from cosmic rays in the area of the
detector.
