Amprobe 33XR-A Professional-Digital-Multimeter - Manual (Page 10)

4
Measuring DC Current See Figure -3-
1. Set the Range Switch to an appropriate A range.
Select the highest range and work down if the current level is unknown.
2. Connect the Test Leads: Red to mA or 10 A, Black to COM
3. Turn off power to the circuit being measured.
4. Open the test circuit (X) to establish measurements points.
5. Connect the Test Probes in series with the load.
6. Turn on power to the circuit being measured.
7. Read the display, and, if necessary, fix any overload (o) conditions.
Measuring AC Current See Figure -4-
1. Set the Range Switch to an appropriate a range.
Select the highest range and work down if the current level is unknown.
2. Connect the Test Leads: Red to mA or 10 A, Black to COM
3. Turn off power to the circuit being measured.
4. Open the test circuit (X) to establish measurements points.
5. Connect the Test Probes in series with the load.
6. Turn on power to the circuit being measured.
7. Read the display, and, if necessary, fix any overload (o) conditions.
Measuring Resistance See Figure -5-
1. Set the Range Switch to an appropriate
Ω range.
Select the highest range and work down if the resistance level is unknown.
2. Connect the Test Leads: Red to E, Black to COM
3. Turn off power to the circuit being measured. Never measure resistance across
a voltage source or on a powered circuit.
4. Discharge any capacitors that may influence the reading.
5. Connect the Test Probes across the resistance.
6. Read the display. If o appears on the highest range, the resistance is too large
to be measured.
Measuring Continuity See Figure -6-
1. Set the Range Switch to R.
2. Connect the Test Leads: Red to E, Black to COM
3. Turn off power to the circuit being measured.
4. Discharge any capacitors that may influence the reading.
5. Connect the Test Probes across the resistance.
6. Listen for the tone that indicates continuity (< 35
Ω).
Checking Diodes See Figure -7-
1. Set the Range Switch to G.
2. Connect the Test Leads: Red to E, Black to COM
3. Turn off power to the circuit being measured.
4. Free at least one end of the diode from the circuit.
5. Connect the Test Probes across the diode.
6. Read the display. A good diode has a forward voltage drop of about 0.6 V. An
open or reverse biased diode will read o.