Underranging And Overranging Conditions; Battery And Bias Annunciators - Fluke TRACKER 90100 Operator's Manual

2.4.8.3 Underranging and Overranging Conditions

The 35360A TRACKER Display displays an underrange indicator when a preset threshold has not yet
been reached, and an overrange indicator when the electrometer's maximum limit has been exceeded
(see Figures 2-22 and 2-23).
An underrange occurs in the percent-of-center measurement mode when the central exposure is too
small to precisely calculate percentages.
Figure 2-22. Underranging the Electrometer
Figure 2-23. Overranging the Top and Night Channels of the Electrometer
Table 2-1 summarizes the underrange and overrange conditions and results.
Table 2-1. Underrange and Overrange Conditions
Measurement Mode
Absolute
Percent-of-Center
Percent-of-Center
Percent-of-Center

2.4.9 Battery and Bias Annunciators

As already discussed, the 35360A TRACKER Display continuously monitors the ion chamber bias and
battery voltages. If either one of these values is outside the specified range, the 35360A TRACKER
displays an annunciator to indicate the error. Table 2-2 specifies these annunciators.
Table 2-2. Bias and Battery Annunciators
Condition
Low Bias voltage
High Bias voltage
Low Battery voltage
Condition
Overrange a chamber
Exposure at center chamber too small to
calculate percentages
A peripheral chamber overranges
while center chamber is within range limit
Center chamber overranges
Annunciator
LoBias
HiBias
LoBat
Operation
Operation Instructions
Chamber Reading
OVER for chamber
UNDER for all peripheral chambers
OVER for peripheral chamber
OVER for all chambers
2
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