Model 702i and 711i
Technical Manual
Section 7
Ludlum Measurements, Inc.
Page 7-1
December 2018
General Operation
Turning the Unit On and Off
Turn on the Model 702i or 711i unit by holding down the B
ACK
/ key until the status screen
appears. The instrument will automatically begin a self test, and the status will be indicated on the
screen. (See Section 2 for more information about this screen.)
Scintillation detectors normally stabilize about 10 minutes after the power is turned on, assuming a
stable temperature environment. However, the Model 702i unit has a built-in stabilization feature
that will generally complete a recalibration within three minutes. During this time, it will display an
informational message at the bottom of the screen indicating that a calibration is in progress.
Although data can still be collected while the unit is stabilizing in an emergency, the built-in
analytical software may not make correct identifications during this time. When the informational
message at the bottom of the screen goes away, the system is ready to use.
Whenever the Model 702i or 711i unit is turned off, all information is saved on the CompactFlash
card, allowing you to restart the instrument without losing calibrations or other information. The
real-time clock has a separate internal lithium battery that keeps it running even when there is no
other power source.
To turn the instrument off, press and hold the B
ACK
/ key. After one second, a message will
appear and count down three seconds before the system turns off. In the rare event of a system
lock-up, it may be necessary to hold the key down for a longer period of time (10 seconds) in order
to engage the fail-safe, power-down mechanism.
Search Modes
The “search” modes are the modes normally used to detect the presence of radioactivity and
determine its location. They respond quickly and make it easy to tell if something has changed, but
give less detailed analytical results. In these modes, the instrument continuously takes readings,
searches for isotopes, and analyzes them for dose rate and other measurements.
There are four search modes available –
Dial
,
Finder
,
Bars
, and
Spectrum
. Only
Dial
and
Finder
are
enabled by default when logged in as
User
. However, your
Administrator
may change which
screens are enabled, so that it is easier to quickly access the most important information for your
particular response plan.
There are a number of elements that appear on all search mode screens. These are shown on the
Dial
screen in Figure 6.
Section
7
