AM300 V1.1 6/07

6

Resistance Measurements

WARNING: To avoid damage to the meter, do not apply voltage to the meter when

measuring resistance. Ensure that the circuit, device, or component under test is

disconnected from power before measuring resistance.

1.

Insert the black test lead into the negative COM terminal and the

red test lead into the OHMS positive terminal.

2.

Set the display scale to the OHMS position using the thumbwheel

switch.

3.

Ensure that the Pointer Lock switch is set to the right-most

position so that the pointer may freely move.

4.

With the test leads open, adjust the meter zero so that the pointer

is over the

∞ symbol.

5.

Touch the test lead tips together and adjust the 0 Ohms adjust

until the pointer is over the 0 ohms position.

6.

Touch the test probe tips across the circuit or component under

test.

7.

The analog display pointer will indicate the resistance reading.

Pointer Lock Function

The Pointer Lock switch freezes the pointer’s position and can be used as a ‘data hold’

feature. This feature is useful in dimly lit or hard to reach locations.

Maintenance

WARNING: To avoid electrical shock, disconnect the meter from any circuit and remove the test leads from

the input terminals before opening the case. Do not operate the meter with an open case.

Cleaning and Storage

Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or

solvents. If the meter is not to be used for 60 days or more, remove the battery and store it

separately.

Battery and Fuse Replacement

1.

Remove the two (2) Phillips head screws at the rear of the meter.

2.

Carefully open the meter housing.

3.

Replace the 1.5V ‘AA’ battery if necessary

4.

Replace the fuse if necessary with a 0.5A / 250V glass fuse (6mm x 30mm) or

equivalent. Note that a spare fuse is provided inside the meter housing.

5.

Close the meter and replace the meter screws securely.

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