Rion NL-42A, Instruction Manual, Page: 57 / 154

39
Calibration
Acoustic calibration (with Sound Calibrator NC-75/NC-74
or Pistonphone NC-72B/NC-72A)
Note
When using the Pistonphone NC-72B/NC-72A, set
the frequency weighting of the NL-42A/NL-52A
as Z or C.
For acoustic calibration, a sound calibrator or a pistonphone is mounted to the
microphone of the NL-42A/NL-52A, and adjustment is performed so that the
reading of the meter is equal to the sound pressure level inside the coupler.
1. Turn off the Sound Calibrator NC-75/NC-74 or the Pistonphone NC-72B/
NC-72A.
2. Mount the 1/2-inch adapter on the coupler of the Sound Calibrator
NC-75/NC-74 or the Pistonphone NC-72B/NC-72A.
3. Insert the microphone very
carefully and slowly
all the way into
the coupler.
Important
Be very careful when inserting and removing the
microphone to and from the Sound Calibrator
NC-75/NC-74 or the Pistonphone NC-72B/NC-
72A, to avoid a sudden pressure buildup which
could destroy the membrane of the microphone.
4. Set the power switch of the Sound Calibrator NC-75/NC-74 or the
Pistonphone NC-72B/NC-72A to ON.
Coupler
Pistonphone NC-72A
1/2-inch adapter
for NC-72A
Pistonphone NC-72B
1/2-inch adapter
for NC-72B
1/2-inch adapter
for NC-75
Sound Calibrator NC-75
1/2-inch adapter
for NC-74
Sound Calibrator NC-74
Coupler
Coupler
Coupler