Measuring Relative Frequency; Relative Frequency Example - Agilent Technologies 53151A Operating Manual

Chapter 2 Operating Your Frequency Counter

Measuring Relative Frequency

Measuring Relative Frequency

You can measure the difference in frequency from one measurement to
another (frequency drift) or between two separate input signals using the
Relative Frequency function.

Relative Frequency Example

Press the Shift key, and then press the Rel Freq (FREQ Offset On/Off)
key. The Shift annunciator activates when you press the Shift key. When
you press the Rel Freq (FREQ Offset On/Off) key, the Shift annunciator
Ch 2
Rel Freq
disappears, and the Rel Freq annunciator in the upper-left corner of the
display activates. At the same time, the Counter saves the frequency
measurement it was displaying at the time you pressed the Rel Freq key,
and it computes and displays the difference between that measurement
and the current measurement.
You can also use the Relative Frequency function to measure the
difference between two different signals. To do this, activate the Relative
Frequency function, as described in the previous paragraph, disconnect
the cable supplying the signal to the input connector, and then connect the
second signal to the same input connector. The value displayed when the
Counter acquires the second signal is the frequency difference between
the two signals.
2-20 Operating Guide