Measuring Duty Cycle; Figure 2-38 Duty Cycle Display - Agilent Technologies u1273a User Manual

2 Making Measurements
Measuring Frequency

Measuring duty cycle

N O T E
82
The duty cycle (or duty factor) of a repetitive pulse train is the ratio of the
positive or negative pulse width to the period expressed as a percentage,
as shown in Figure 2-35.
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
width, which can be checked by measuring the duty cycle.
1 To measure the duty cycle, position the rotary switch on
one of the functions allowing frequency measurements
shown in Table 2-
2 Press
until the measurements are displayed as a
percentage (%). Probe the test points, and read the
display.

Figure 2-38 Duty cycle display

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. indicates a positive pulse and
negative pulse. To change the polarity being measured,
press .
Dual
Exit
20.
U1273A/U1273AX User's Guide
indicates a