Temperature Measurements; Autoranging/Manual Range Selection - Extech Instruments EX540 User Manual

TEMPERATURE MEASUREMENTS

1. Set the function switch to the Temp position.
2. Insert the Temperature Probe into the input jacks, making sure to
observe the correct polarity.
3. Press the MODE button to indicate "ºF" or "ºC"
4. Touch the Temperature Probe head to the part whose temperature
you wish to measure. Keep the probe touching the part under test
until the reading stabilizes (about 30 seconds).
5. Read the temperature in the display.
Note: The temperature probe is fitted with a type K mini connector. A mini connector to
banana connector adaptor is supplied for connection to the input banana jacks.
FREQUENCY (DUTY CYCLE) MEASUREMENTS (ELECTRONIC)
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. Touch the test probe tips to the circuit under test.
4. Read the frequency on the display.
5. Press the MODE button to indicate "%".
6. Read the % duty cycle in the display.
% 4 – 20mA MEASUREMENTS
1. Set up and connect as described for DC mA measurements.
2. Set the rotary function switch to the 4-20mA% position.
3. The meter will display loop current as a % with 0mA=-25%, 4mA=0%, 20mA=100%,
and 24mA=125%.

AUTORANGING/MANUAL RANGE SELECTION

When the meter is first turned on, it automatically goes into AutoRanging. This
automatically selects the best range for the measurements being made and is generally
the best mode for most measurements. For measurement situations requiring that a range
be manually selected, perform the following:
1. Press the RANGE key. The "AUTO" display indicator will turn off.
2. Press the RANGE key to step through the available ranges until you select the range
you want.
3. To exit the Manual Ranging mode and return to Autoranging, press EXIT
Note: Manual ranging does not apply for the Temperature functions.
MAX/MIN
1. Press the MAX/MIN key to activate the MAX/MIN recording mode. The display icon
"MAX" will appear. The meterleft auxiliary displaywill display and hold the maximum
reading and will update only when a new "max" occurs.The display icon "MIN" will
appear. The right auxiliary displaymeter will display and hold the minimum reading
and will update only when a new "min" occurs.
2. To exit MAX/MIN mode press EXIT
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