Thermo Scientific SAM12, Руководство пользователя

Страница: 91 / 176

Issue: 1.0 Operating Instructions
Thermo Fisher Scientific SAM12 User Manual 5-51
monitoring can re-commence, the
door needs to be opened and shut
again.
In a two-door SAM12, if the back
door is opened during Normal
Background Monitoring, the
"ILLEGAL DOOR
SEQUENCE" message is
displayed. To re-establish
Normal Background Monitoring,
the door(s) must be shut.
See
Doors (page 5-13) for more
information.
When a changing background has been detected or the
instrument does not have a valid background (e.g. at System
Startup), the system establishes a new background radiation
measurement.
Each 10 second Background count for each detector, is checked
against user defined statistical limits for variance from the
stored average for that channel. If the count is acceptable it is
incorporated into the stored average, otherwise the stored
average for all channels is discarded, the blue Alarm lamp will
light and “Updating Background - Please Wait” message is
displayed while a fresh 100 second Background is accumulated
- see
Background Update (page 6-5) for more information.
After every successful 10 second Background update period,
the minimum monitoring time required to give the required
measurement certainty is automatically re-calculated. The
calculated monitoring time is rounded-up to the nearest second
and used when monitoring articles. If the calculated time is
greater than the Maximum Monitoring Time, see
Description of
Parameters Used in Calculations (page 6-2) and Params 2 (page
5-10) and a “High Background - Out of Use” message will be
displayed – see Notes regarding High Background (page 5-62)
for more information.
Monitoring
The SAM12 is available with a one or two door option. In a
two door SAM12, there is a front door and rear door. In a
single door SAM12, only the front door is fitted. See
Doors
(page 5-13) for more information.
CAUTION: CARE MUST BE TAKEN TO AVOID
SWINGING THE DOORS WIDE OPEN WITHOUT
Notes regarding Changing
Background
Door Operations