Ludlum Measurements 2241-3, Manual

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Model 2241-3 & 3i Technical Manual
Section 4
Ludlum Measurements, Inc. Page 4-1 January 2016
Identification of Controls and
Functions
Display
The Model 2241-3 utilizes a four-digit liquid crystal display (LCD) with a
two-digit overflow (
SCALER
mode) and moving decimal point. The two
smaller digits located in the lower right corner of the display indicate
counter
OVERFLOW
when in the scaler counting mode (equivalent to a
six-digit scaler) or exponential power when in the parameter setup
mode. The upper right corner of the LCD displays units and
multiplier(s) - R/hr, mR/hr, or µR/hr; Sv/h, mSv/h or µSv/h; C/m,
kC/m, C/s or kC/s. The bottom part of the readout displays the
ALARM
,
ALERT
,
OFLOW
,
OVERLOAD
(not used) enunciators and the
low-battery icon.
COUNTING
indicates that the scaler mode has been initiated
and is in the counting process.
Display Status Definitions
ALARM
: Ratemeter or scaler count has increased above the preset alarm
threshold. An audible continuous tone will accompany the latching
ALARM
condition. Depressing
RESET
will acknowledge the audible ratemeter and/or
scaler alarm. Depressing
RESET
a second time will reset the ratemeter
reading and ratemeter alarm. To reset the scaler
ALARM
, depress the
COUNT
switch located in the carrying handle to re-initiate the scaler count cycle.
ALERT
: Ratemeter count has increased above the preset alert threshold. To
reset an
ALERT
condition, press
RESET
once if in the non-alarm condition
and twice if in an alarm condition. (The first depression in the alarm
condition acknowledges the audible alarm.) The ratemeter will reset to the
minimum displayable reading each time the alert is reset.
OFLOW (Overflow)
[
RATEMETER
mode]: Indicates that the incoming count
exceeds the capability to display stable or reliable readings corresponding to
the radiation level being measured. The overflow symbol will appear when
the ratemeter exceeds 100 kcps or if the dead time correction is greater than
75%.
OFLOW
will appear in the
SCALER
mode when the six-digit display
(four digits display and two overflow digits in right corner) reaches
“999999” and starts to roll over again.
Section
4