Elenco Digital Multimeter - Manual (Page 9)

Measuring Duty Cycle
Duty cycle (or duty factor) is the percentage of time a signal is above
or below a trigger level during one cycle (Figure 16).
To measure duty cycle, proceed as follows:
1. Turn on the meter, then set up the meter as shown in Figure 15.
2. Insert the black test lead into the COM terminal and the red test
lead into the terminal.
3. Set the Function Rotary Switch to the Hz position. Then press
Hz/DUTY once to select DUTY Cycle measurement (then, a “%”
symbol is indicated on the display).
4. Connect the test leads to the circuit under test. The measured
value is shown on the display.
Figure 15. Duty Cycle Measurement
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3. REL Δ (relative measurement)
Press the REL Δ button to use the relative measuring function and
a “ Δ ” symbol appears on the LCD. The result of the relative
measurement is the difference between the measuring value and
the reference value. The reference value is produced the same as
the momentary value by press the
REL Δ button. Press the REL Δ
button again to exit this function and the “ Δ ” symbol disappears from
the display. This button does not affect the frequency, duty cycle,
diode and continuity test functions.
4. HOLD/ (data hold / backlight)
Press this button for less than 2 seconds and the meter will enter
the data hold mode and the “
HOLD ” symbol will appear on the
LCD. The value shown on the display will stay at its current reading
while this function is active. Pressing the button again will exit the
HOLD mode and the “
HOLD ” symbol will disappear. As a data hold
function, this button does not button does not have any effect on
the diode and continuity test functions.
The secondary function of this button is to enable the LCD backlight
feature. If you press the button for more than two seconds, the
backlight will illuminate. If you press the button again for more than
two seconds, the backlight will turn off. The backlight will turn off
automatically after eight seconds have elapsed.
5. Hz/DUTY (frequency and duty cycle measurement switch button)
When you make a Frequency and Duty Cycle measurement, AC
voltage, or AC current measurement, press this button to switch
between the Hz or duty cycle test mode.
6. RESET (reset button)
Press this button to clear all values and to restart the meter.
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HOLD
HOLD
Signal