Level Calibration with a Pistonphone
Level calibration with a pistonphone requires that a calibration adapter is used.
• For 1/2” microphones, the RA0048 1/2” Calibration Adapter must be used. It is an accessory
included with your pistonphone.
• For 1/4” microphones, the RA0331 1/4” Calibration Adapter must be used. It is part of the
45CC-configurations that use 1/4” microphones.
Important.
It is important that the adapter is pushed as far down into the pistonphone as it will
go. To ensure this, you must either tighten the pistonphone’s collar to ensure that it is in its lowest
possible position, or remove it entirely, as shown below.
G.R.A.S.
Pistonphone
Type 42AP
Serial No. XXXXX
IEC 60942 (2003) LS
Lock
Signature Series
G.R.A.S.
Pistonphone
Type 42AP
Serial No. XXXXX
IEC 60942 (2003) LS
Signature Series
The adapters have identical outer dimen-
sions, and the procedure for mounting them
is the same.
1.
Select the appropriate adapter for the
microphone you want to calibrate.
2. Remove the pistonphone collar by turning
it counterclockwise and lifting it up.
3. Remove the O-ring mounted in the piston
-
phone coupler entrance.
4.
Push the adapter as far down into the pis-
tonphone as it will go.
You are now ready to mount he microphone
into the adapter.
Fig. 13.
Removing the collar before mounting the
adapter
For further information, see the manual for your pistonphone.
Level Calibration with a Sound Calibrator
• For 1/2” microphones, the RA0297 1/2” Calibration Adapter must be used when. It is an acces
-
sory included with your calibrator.
• For 1/4” microphones, the RA0331 1/4” Calibration Adapter must be used. It is part of the
45CC-configurations that use 1/4” microphones.
For further information, see the manual for your calibrator.
Instruction Manual
3 0 | GRAS 45CC Headphone Test Fixture
