Measuring Frequency And Period - Fluke 8845A User Manual

8845A/8846A
Users Manual

Measuring Frequency and Period

The Meter measures the frequency, or period of ac signals between 3 Hz and 1 MHz,
applied between the Meter's HI and LO connectors.
The G key not only activates the Meter's Frequency/Period function, but also toggles
the Meter's primary display between the signal's frequency and period measurement.
Therefore, whether a frequency or period measurement appears after pressing G
depends on the condition this function was left in the last time it was used.
To make a frequency measurement:
1. Press G.
2. Connect the Meter to the signal as shown in Figure 4-1.
To make a period measurement:
1. Press G.
2. Connect the Meter to the signal as shown in Figure 4-1.
4-6
accommodate the various impedances that a dBm measurement can be
made across, the Meter allows for the selection of 21 different
impedance values.
To set the dB reference impedance:
1. Press L.
2. Press the soft key labeled dBm REF.
The available impedance settings are presented in sets of three
values. To move to a higher set of impedance values, press
++
values.
3. With the impedance highlighted, press the soft key under the
value selected.
2ND MEAS Cycles the secondary display through the measurement functions
listed below, and then off. When a second measurement function is
selected, the 2ND MEAS soft key label is highlighted.
VDC - Displays the dc voltage on which the ac signal may be riding.
Frequency - Displays the frequency of the ac signal applied to the
Input HI and LO connectors of the Meter.
0.000000
F1
If S is displayed, press G again to switch the primary display to frequency.
If Hz is displayed, press G again to switch the primary display to period.
-->. Press <-- -- to go to a lower set of impedance
Hz
F2 F3 F4 F5
caw06f.eps