Keysight Technologies U1273A Guide De L'utilisateur page 104

2 Making Measurements
Measuring duty cycle
The duty cycle (or duty factor) of a repetitive pulse train is the ratio of the
NOTE
positive or negative pulse width to the period expressed as a percentage, as
shown in
The duty-cycle function is optimized for measuring the on or off time of logic and
switching signals. Systems such as electronic fuel injection systems and
switching power supplies are controlled by pulses of varying wid th, which can
be checked by measuring the duty cycle.
1 To measure the duty cycle, position the rotary switch on one of the functions
2 Press
Figure 2-40
The duty cycle percentage 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 duty cycle but indicates the voltage or ampere value of
the input signal.
The pulse polarity is displayed to the left of the duty cycle value.
positive pulse and
measured, press
Press
measurements.
Press
104
Figure 2-37.
allowing frequency measurements shown in
until the measurements are displayed as a percentage (%). Probe
the test points, and read the display.
Duty cycle display
indicates a negative pulse. To change the polarity being
.
Dual
Exit
to cycle through the frequency, pulse width, and duty cycle
for more than 1 second to exit the duty cycle measurement function.
Dual
Exit
Table 2-20.
Keysight U1273A/U1273AX User's Guide
indicates a