Rion NC-74, Instruction Manual

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9
Measurement
5. Set the power switch of the NC-74 to ON. If
the battery voltage of the NC-74 is normal,
the LED lights up. If the voltage is too low,
the LED fl ashes. In such a case, replace both
batteries with fresh ones. If the batteries are
totally exhausted, the LED will not light at
all. The batteries must be replaced immediately.
6. Wait until the sound level meter reading has stabilized. Then read the indicated
value. Verify that this reading is at least 20 dB higher than the reading obtained
in step 3.
Important
If the difference is less than 20 dB, ambient noise has too
much infl uence on the measurement, and correct calibration
will not be possible.
LED
Power switch