17
METHOD OF MEASURING
DC/AC VOLTAGE.
Exercise extreme care when measuring voltages, which are over 48 volt.
1. Connect the red test lead to the V/
Ω
input jack and the black test lead to the COM
jack.
2. Set the rotary switch to the desired V= (DC) or V~ (AC) position. If the magnitude of
the voltage is not known, set the rotary switch to the highest range and reduce until a
satisfactory reading is obtained.
3. Connect the test leads to the device or circuit being measured.
4. Read the voltage and, if applicable the polarity, on the display.
When set to 1000 VDC or 750 V(AC), the display gives a high-voltage symbol. Please pay
extra attention.
DC/AC CURRENT.
Current is being measured by making an interruption in the circuit and by
positioning the test leads at those places.
Always switch off power to the device under test prior to make an inter-
ruption and never remove the test leads before the power is switched off
again.
Be aware of the high switch-on current of some devices like trans-
formers, motors, coils etc.
1. Connect the red test lead to the A input jack (TM-36) or to the mA input jack (TM-56)
for current measurements up to 2A (TM-36) or 200mA (TM-56); connect the black
test lead to the COM input jack.
2. Set the rotary switch to the desired A= (direct current) or A~ (alternating current)
position. If the magnitude of the current is not known, set the rotary switch to the
highest range and reduce until a satisfactory reading is obtained.
3. Connect the test leads to the interruption in the circuit.
4. Switch-ON power to the device under test and read the current value on the digital
display.
5. Switch-OFF power to the device prior to remove the test leads.
TM-36:
If the current is in between 2A and 10A, connect the red test lead to the 10A input
jack. Set the rotary switch into position 10A.
TM-56:
If the current is in between 200mA and 20A, connect the red test lead to the 20A
input jack. Set the rotary switch into position 20A.
Attention:
these high currents may not be measured for a period, which exceeds 10 to 15
seconds. For safety reasons the tester must than cool down for about 15 minutes.
The 20A input jack of the TM-56 is NOT FUSED.
