Models 375-31H Area Monitor with Neutron Detector
Section 2
Ludlum Measurements, Inc.
Page 2-3
January 2021
*
Model 375 Series One
: In the special case of the Model 375 Series One,
make note of the following changes resulting from firmware modification:
With the
RANGE
dipswitch in the left position, two decimal places will
be displayed.
With the
RANGE
dipswitch in the right position, no decimal place will be
displayed.
Calibration constant will be displayed in cps per unit, instead of cpm per
unit.
Dead Time Correction will display in 10
ths
of microseconds (i.e. 50 µsec
instead of 5 µsec).
Setting Alarm Points
The
LOW ALARM
and
HIGH ALARM
points can only be changed while the
instrument is in calibration mode. Switch the top dipswitch
CAL MODE
(behind the calibration cover) to the right to place the instrument into
calibration mode.
Changing alarm points is done by holding down the corresponding
parameter key and pressing the up or down arrow buttons. Alarm points can
be set in the range of 0.1 to 9999*. When an alarm point is changed, the
instrument will sound an audible beep to confirm the saving of the
parameter, and will then return to displaying the current radiation level.
Note:
Once the alarm point(s) is set, it is important to remember to
switch the
CAL MODE
switch back to the left. This action
protects the parameters from inadvertent changes.
Return for Repair and Calibration
To return an instrument for repair or calibration, provide sufficient packing
material to prevent damage during shipment.
Every returned instrument must be accompanied by an
Instrument Return
Form
, which can be downloaded from the Ludlum website at
. Find the form by clicking the “Support” tab and
selecting “Repair and Calibration” from the drop-down menu. Then choose
the appropriate Repair and Calibration division where you will find a link to
the form.
