Temperature Measurements; Autoranging/Manual Range Selection - Extech Instruments EX540-NIST 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 meter left auxiliary display will display and hold the maximum reading and will
update only when a new "max" occurs. The display icon "MIN" will appear. The right auxiliary
display meter 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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