Simpson 270-5, Инструкция по эксплуатации

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d. Turn OFF power.
e. Connect the test leads across the cir-
cuit being measured with the black
test lead to the ground side.
f. Turn on power in the test circuit. Read
the output voltage on the appropri-
ate AC voltage scale. For the 0-2.5V
range, read the value directly on the
scale marked 2.5 VAC. For the 10V,
50V, or 250V ranges, use the red scale
marked AC and read the black fig-
ures immediately above the scale.
4.12 Decibel Measurement (-20 to +50 dB)
Some industries measure in terms of voltage or current ratios (decibels) based
on a specific reference level. The dB scale on the 270 serves this purpose and is
calibrated to a reference level (zero dB) or 0.001 watt into 600 ohms. The scale
calibration of -20 to +10 dB is for the 0-2.5V range (zero dB = 0.775V). Higher
ranges may be used by adding an appropriate dB value to the reading in accor-
dance with chart on the following page.
a. Review the safety precautions in
paragraph 4.1.
b. Set the functions switch at AC (figure
4-6).
c. Plug the black test lead into the -
COMMON jack and the red test lead
into the + jack.
c. Use operating instructions for AC
VOLTAGE MEASUREMENT, 0-2.5/
10/50/250/500V RANGES (para-
graph 4.9).
Do not use the 500V range for decibel
readings.
d. Read decibels on the bottom scale
marked dB. For the 10/50/250V
ranges, add the appropriate factor
from the following chart.
COMMON
ALL TERMINALS IKV. MAX
A.C.
OUTPUT
350 VDC
MAX 270
2.5V.
IV.
10V.
50V.
AMPS
250V.
WARNING
READ MANUAL BEFORE USE
Figure 4-5. Jacks and Switch for
Output Measurement
COMMON COMMON
ALL TERMINALS IKV. MAX
270
2.5V.
1V.
10V.
50V.
AMPS
250V.
A.C.
WARNING
READ MANUAL BEFORE USE
Figure 4-6. Jacks and Switch
Positions for Measuring Decibels