User guide

MEASUREMENT OPERATION

2. Set the rotary switch to Hz%; frequency measurement is set to (Hz) as default,

otherwise press the Hz% button (GDM-360/397/398) or the yellow button

(GDM-461) to select Hz measurement mode.

3. Connect the test leads to the DUT.

The measured value shows on the display.

4. If you need to measure the duty cycle, press the Hz % button (GDM-

360/397/398) or the yellow button (GDM-461) to select % measurement mode

Note

 Input Amplitude: (DC offset is zero)

 GDM-360/397/398: When 10Hz ~ 10MHz: 200mV ≤a ≤ 30Vrms

 GDM-461:When 10Hz ~ 10MHz: 300mV ≤a ≤ 30Vrms

When ≈10MHz ~ 40MHz: 400mV ≤ a ≤ 30Vrms

When ≥ 40MHz: unspecified

 For GDM-461: When measuring Audio frequency, if the input voltage is more

than 15volts the meter will simulate the sound at the same frequency.

 When frequency measurement has been completed, disconnect the connection

between the testing leads and the circuit under test, and remove the testing leads

away from the input terminals of the Meter.