Fluke 90100 manual Underranging and Overranging Conditions, Battery and Bias Annunciators

Operation

Operation Instructions 2

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	Condition
Absolute	Overrange a chamber
Percent-of-Center	Exposure at center chamber too small to
	calculate percentages
Percent-of-Center	A peripheral chamber overranges
	while center chamber is within range limit
Percent-of-Center	Center chamber overranges

Chamber Reading

OVER for chamber

UNDER for all peripheral chambers

OVER for peripheral chamber

OVER for all chambers

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	Annunciator
Low Bias voltage	LoBias
High Bias voltage	HiBias
Low Battery voltage	LoBat

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