Extech Instruments EX845 User Manual page 9

Type K Temperature Measurements
1. Set the function switch to the K Temp position.
2. Insert the Temperature Probe into the negative COM and the
TEMP jacks, observing polarity.
3. Touch the Temperature Probe tip to the device under test.
Continue to touch the part under test with the probe until the
stabilizes.
4. Read the temperature on the display. The digital reading will indicate
decimal point and value.
WARNING: To avoid electric shock, be sure the thermocouple probe
before changing to another measurement function.
Note: An open input or a temperature overrange the meter will display
Note: See the "Temperature Units" paragraph to select °F or °C
Continuity Measurements
Insert the black test lead into the negative COM terminal and the red test lead into the Ω positive
1.
terminal.
2. Set the function switch to the
3. Use the MODE button to select continuity
pressed.
4. Touch the test probe tips across the circuit or component under test.
5. If the resistance is < 40Ω, a tone will sound.
Diode Test
1. Insert the black test lead banana plug into the negative COM jack and the red test
lead banana plug into the
2. Turn the function switch to
(diode symbol will appear on the LCD when in Diode test mode)
3. Touch the test probe tips to the diode or semiconductor junction under test. Note the meter reading
4. Reverse the test lead polarity by reversing the red and black leads. Note this reading
5. The diode or junction can be evaluated as follows:
If one reading displays a value (typically 0.400V to 0.900V) and the other reading displays OL, the
diode is good.
If both readings display OL the device is open.
If both readings are very small or '0', the device is shorted.
position.
•) )
)
. The display icons will change when the MODE button is
•) )
)
positive jack
position. Use the MODE button to select the diode function if necessary
9
positive
reading
the proper
has been removed
"OL" and beep.