G.R.A.S. Sound & Vibration
Pistonphone Type 42AC - Page 9
3.
Handling and Operation
3.1
Shipment and Transport
Before any major shipment where rough handling is to be expected, remove the batteries to pro
-
tect connectors and other internal parts from accidental damage.
Before shipment, remove the batteries and wrap separately.
Assure cautious handling during transport.
3.2 Batteries
The Pistonphone runs on four 1.5 V batteries (type AA [LR6]). To install or replace the batter
-
ies, remove first the lid of the battery compartment which is held in place by the screw shown in
Fig. 3.1. Slide the lid in the direction shown after removing the screw. Insert four new batteries
observing the correct polarity as indicated on the figure inside the battery compartment.
The Pistonphone can operate continuously for about 20 hours on a new set of batteries.
Remove the battery as soon as it is discharged or if the 42AC is stored for a
prolonged period of time. Leakage from the batteries may otherwise destroy
the electronic components.
3.3
Calibrating Microphones
3.3.1 Microphone Size
The Pistonphone is normally delivered ready to calibrate ½
"
microphones. For ¼
"
and ⅛
"
microphones, special adapters are included and for 1
"
microphones, a 1
"
coupler (available from
G.R.A.S.) has to be fitted. Each case is described in the following four sections.
3.3.2 ½
"
Microphones
To calibrate a ½
"
measurement microphone, first loosen the microphone retention collar as
shown in Fig. 3.2. Then insert the microphone into the ½
"
coupler
1
, as shown in Fig. 3.3. Make
sure that the microphone is all the way in, then tighten the microphone retention ring so that the
microphone is held firmly in place.
Fig. 3.1 Access to batteries
1
The ½" coupler is individual calibrated with the pistonphone, and these must be considered as a pair
Fig. 3.2 Loosening the microphone retention collar
