Fluke PM6669 Operator's Manual page 14

FUNCTION AND RANGE
The counter measures the positive pulse width of the
signal on Input-A.
Range:
100 ns to 200 000 000 s.
The set Measuring-time controls the time during
which the main gate is opened, allowing pulses to en-
ter the counting logic. A longer Measuring-time gives
higher resolution readouts with more digits displayed.
The time the gate is open is not exactly the preset
Measuring-time, because the Frequency Counter syn-
chronizes the measurement with the input signal in or-
der to measure complete periods. If the period of the
input signal is longer than the set Measuring-time, the
main gate does not close again until the period is
completed.
For PER A and WIDTH exactly one period or one
time interval is measured. The minimum result possi-
ble is 100 ns.
The display time will be 100 ms.
When set to SINGLE, FREQ A and, RPM A, the
Measuring-time is one cycle of the input signal or
3 ms, whichever is longest. When set to SINGLE and
FREQ B, the Measuring-time is 3 ms.
A Frequency-A measurement will result in 6-7 digits
on the display.
A Frequency-A measurement will result in 7-8 digits
on the display.
A Frequency-A measurement will result in 8-9 digits
on the display.
OPERATING INSTRUCTIONS
HINTS AND COMMENTS
If you are interested in the negative pulse width
instead; first measure the period and make a note of
the result, then measure the pulse width and
substract it from the period reading.
If you wish to do one measurement instead of
repetitive measurements, see DISPL HOLD.
The input frequency is limited to 16 MHz for FREQ A,
PER A, and RPM A.
If external reference is used, the EXT REF indicator
will not be switched-on until after the first
measurement.
PM 6669 - OPERATORS MANUAL
Page: 13