Keysight U1281A Guide De L'utilisateur page 90

2 Making Measurements
Figure 2-31
The frequency of the input signal is shown in the primary display. The voltage or ampere
value of the signal is shown in the secondary display. The bar graph does not indicate
frequency but indicates the voltage or ampere value of the input signal.
– Measuring the frequency of a signal helps detect the presence of harmonic currents in
NOTE
neutral conductors and determines whether these neutral currents are the result of
unbalanced phases or non-linear loads.
– Frequency is the number of cycles a signal completes each second. Frequency is
defined as 1/Period. Period is defined as the time between the middle threshold
crossings of two consecutive, like-polarity edges, as shown in Figure 2-32.
– The multimeter measures the frequency of a voltage or current signal by counting the
number of times the signal crosses a threshold level within a specified period of time.
– To obtain the best measuring results for frequency measurements, please use the AC
measuring path.
Rise Time
Figure 2-32
90
Frequency display
Fall Time
+ Width
Period
Frequency, pulse width, and duty cycle measurements
- Width
Keysight U1281A/U1282A User's Guide
90%
50%
10%