EXTECH EX840 [7/12] Continuity measurements

EX840-EU-EN-V5.3-3/12

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 positive 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 reading stabilizes.

4. Read the temperature on the display. The digital reading will indicate the

proper decimal point and value.

WARNING: To avoid electric shock, be sure the thermocouple probe has been

removed before changing to another measurement function.

Note: An open input or a temperature overrange the meter will display “OL” and

beep.

Note: See the “Temperature Units” paragraph to select °F or °C

Note: The temperature range of the supplied thermocouple probe is -20 to 250°C

(-4 to 482°F)

Continuity Measurements

1. Insert the black test lead into the negative COM terminal and the red test lead into the Ω

positive terminal.

2. Set the function switch to the

•))) position.

3. Use the MODE button to select continuity

•))). The display icons will change when the MODE

button is 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 positive jack

2. Turn the function switch to position. Use the MODE button to select the diode function if

necessary (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.