Tektronix CMC251, Руководство пользователя

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Reference
CMC251 User Manual
13
Making Pulse-Width Measurements
A pulse-width measurement is the time in seconds from one edge of
the signal to the next edge. This measurement is accomplished by
averaging the signal events for a certain number of internal clock
pulses determined by the gate setting. Therefore, the gate setting
determines the resolution (or accuracy) of the reading.
The CMC251 Frequency Counter normally measures the positive
pulse width, but it can measure the negative pulse width using the
external input connector on the rear panel. This method is discussed
in Remote Control of Pulse-Width Measurements
on page 14.
1. Determine the signal voltage level. A good practice is to display
the signal on an oscilloscope and obtain the peak voltage level.
2. Refer to Table 8 and set the frequency counter front-panel buttons
to obtain the best pulse measurements.
Table 8: Pulse Width Measurements
50 mV to 5 V 3 V to 42 V
INPUT VOLTAGE LO (button out) HI (button in)
LOW PASS FILTER OFF (button out) OFF (button out)
PRESCALE No Effect No Effect
3. Press the FUNC button until PULSE A is indicated by a lighted
LED.
4. Connect the signal to the CHANNEL A INPUT connector.
5. Press the GATE button to select the desired display resolution.
See Table 9 for the available resolutions.