Casella CEL CEL-296 - Manual (Page 32)

Figure 9: Attaching the filter set close coupled to a
CEL sound level meter
2. Fit the microphone and preamplifier to the sound level meter
according to the instructions given in its handbook.
3. When the sound level meter to be used is one of the CEL-
493/3, /2N, CEL-275/3, /2, or CEL-383/3, /2 series, go to step 4
When it is one of the earlier versions, it is recommended that
the factory mod for close coupling be implemented.
4. Connect the two instruments close-coupled to each other as
shown in Figure 9 by inserting the plug on the top of the filter
set into the socket on the bottom of the sound level meter.
The locking screw in the filter set is spring loaded to allow the
plug to be inserted fully.
Ensure that the locking screw is correctly aligned with the bush
in the bottom plate of the sound level meter.
Page 32 CEL-296/3 Operator Handbook CEL Instruments Ltd