Capacitance Measurements; Frequency Measurements; Duty Cycle - Extech Instruments 420 User Manual

CAPACITANCE MEASUREMENTS

WARNING: To avoid electric shock, disconnect power to the unit under test and
discharge all capacitors before taking any capacitance measurements. Remove the
batteries and unplug the line cords.
1. Set the rotary function switch to the green
2. Insert the black test lead banana plug into the negative
COM jack.
Insert the red test lead banana plug into the positive
3. Touch the test leads to the capacitor to be tested.
4. Read the capacitance value in the display

FREQUENCY MEASUREMENTS

1. Set the rotary function switch to the green "Hz" position.
2. Insert the black lead banana plug into the negative COM
jack and the red test lead banana plug into the positive Hz
jack.
3. Touch the test probe tips to the circuit under test.
4. Read the frequency on the display.

% DUTY CYCLE

1. Set the rotary function switch to the "Hz" position.
2. Insert the black lead banana plug into the negative COM
jack and the red test lead banana plug into the positive Hz
jack.
3. Press the SELECT key momentarily to select % in the
display.
4. Touch the test probe tips to the circuit under test.
5. Read the % duty cycle on the display.
position.
jack.
10 EX420-EU_ENG V3.1 6/09