Fluke 45 user manual Selecting a Measurement Function, Ranging, E, U, T, Autoranging

Operating the Meter From the Front Panel	3
Selecting a Measurement Function

Table 3-1. Input Limits

FUNCTION

{and FREQ

mADand FREQ

\and FREQ

e

G

All Functions

INPUT TERMINALS

VeG and COM

VeG and COM

100 mA and COM

10A and COM

VeG and COM

VeG and COM

Any terminal to earth

MAXIMUM INPUT

1000V dc

750V ac rms, 1000V peak, 2 x 107 V-Hz normal mode, or 1 x 106 V-Hz common mode (whichever is less)

300 mA dc or ac rms

10A dc or ac rms (or 20A dc or ac rms for 30 sec. Max)

500V dc or ac rms on all ranges

500V dc or ac rms

1000V dc or peak ac

Selecting a Measurement Function

Press a function button (white), shown in Figure 3-5, to select a measurement function To select ac + dc total rms readings, press Zand Y, or Dand C, simultaneously.

When you select a function, annunciators turn on to indicate the function selected. If a reading is shown on the secondary display when a function button is pressed, the secondary display will be turned off.

Ranges and full scale values are summarized in Table 3-2 for voltage, Table 3-3 for current, Table 3-4 for ohms, and Table 3-5 for frequency.

Ranging

(E, U, T)

Ranging operations are performed using the E, U, and Tbuttons (see Figure 3-6).

Autoranging

When you are in the autorange mode, the AUTO annunciator is lit.

In autorange, the meter automatically selects the next higher range when a reading is greater than full scale. If no higher range is available, "OL" (overload) is displayed on the primary or secondary display. The meter automatically selects a lower range when a read- ing is less than approximately 9 % of full scale.

3-5