4. Apply the test leads to the two points in the circuit at
which the voltage is to be measured. When
measuring DC voltage the black lead should be
connected to the more negative point of
measurement. When measuring AC voltage the
polarity does not matter.
5. To read DC voltage use the black “DC” arc directly
below the mirrored arc. Use the numbers whose full
scale reading matches the range selected by the
“selector switch”.
6. To read AC voltage use the red “AC” arc. Use the
numbers whose full scale reading matches the range
selected by the “selector switch”.
7. The dB scales can be used to measure the milliwatt
power dissipation in a 600 load by measuring the AC
voltage across a 600 OHM load. An AC voltage of
0.775 Vrms across 600 OHMS is equal to 1mW or “0”
dB. When converting an AC voltage measurement to
dB take the dB readings from the lowest arc on the
scale plate and then add the appropriate dB correction
as listed in the chart printed in the lower right corner of
the instrument scale plate.
5-2) DC Current Measurements
1. Follow the Preparation for Use procedure in sec. 4.
2. Read all Safety Precautions in sec. 2.
3. Place the function switch to the 20A position,
always start with the highest range.
4. Place the red test lead in the “DC20A” terminal, and
the black test lead in the “COM” terminal.
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6. Please the selector switch on the SP-152A into the
“X1K” position, hold the tips of the Red and Black test
leads together and adjust the “OHMS adjust knob”
until the meter movement pointer reads “0” on the
OHMS scale located at the extreme right side of the
scale plate. If a “0” reading cannot be obtained a
weak battery is the most probable cause. Follow the
battery replacement procedure in sec. 6-1.
Note:
The battery is only used for resistance
measurements with the selector switch in the “X1”,”X10” or
“X1K” positions. The SP-152A can be used in all other
ranges with a weak, dead or missing battery.
7. The SP-152A is now ready for use. Follow the
Measurement procedures in this manual for all
measurements. Read all Safety Precautions in sec. 2
before proceeding.
Sec. 5 OPERATION
5-1) Voltage Measurements
1. Follow the Preparation for Use procedure in sec. 4.
2. Read all Safety Precautions in sec. 2.
CAUTION
1000 Vac/dc is the maximum voltage that can be measured
using this meter. Attempting to measure higher voltages may
result in electrical shock, instrument damage and/or damage to
equipment under test.
3. Select an AC or DC voltage range using the selector
switch that is higher than the maximum voltage to be
measured. If the maximum voltage may be higher
than 1000 Vac/dc, do not attempt to take a
measurement.
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