Ludlum Measurements 48-4203, Manual

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56 CHAPTER 8. ADVANCED FEATURES
Table 8.1: Features That Affect Units in All Modes
UNITS Feature
cpm, cps, counts Deadtime Correction
Bq, dpm,
disintegrations
Dead Time Correction,
Efficiency
R/h, R
Dead Time Correction,
Calibration Constant
Sv/h, Sv, rem/h,
rem
Dead Time Correction,
Calibration Constant,
R to Sv Conversion
These apply to all modes.
8.2.1 R to Sv Conversion
The R to Sv conversion is a setting available in Lumic Calibration software. It defines the con-
version factor between R and Sv. Since the calibration constant is directly tied to R (counts
per R), calibrating Sv requires a correct setting of both calibration constant and R to Sv con-
version.
The rem unit is also affected by the R to Sv conversion. A rem is defined in firmware as being
100x the value of Sv.
Example: An R to Sv conversion factor of 0.0106 will cause a reading of 10.6 mSv/h (1.06
rem/h) while in a 1 R/h field.
8.3 Calibration Expiration Lockout
Calibration expiration lockout timer is a feature that can be configured in the Lumic Calibra-
tion software. It allows setting a date and time that will cause the device to lock out due to
expired calibration.
To enable this feature, the calibration expiration lockout timer DIP switch must be turned
on (see DIP Switches on page 53). The real time clock and the calibration expiration lockout
must also be set correctly in Lumic Calibration software.
A calibration expiration fault (see Calibration Expiration on page 32) that cannot be ac-
knowledged away will persist on the display after the calibration expiration lockout time has
elapsed. The device will not be usable until the lockout timer is reset (during calibration) or
the DIP switch is disabled inside the device.
The real time clock is also required to be set correctly for this feature to function. This in-
strument utilizes a super capacitor to retain the clock settings for a short time during battery
changes. If the batteries are allowed to go completely dead to the point where the device will
not attempt to turn on and the display is completely blank, the real time clock will probably
require being reset. The user will be notified of a reset clock by the date fault (see page 33)
upon power-on after new batteries are installed.
Ludlum Measurements, Inc.