Casella CEL CEL-414 - Manual (Page 21)

4.2Fitting Microphones &
Preamplifiers
Caution
Do not fit any microphone or
preamplifier while the power
is switched ON.
Remember that the microphone is a deli-
cate item, so handle it with care making
sure not to mistreat or drop it. Prevent
the build up of dust or grease on the insu-
lator in the rear cavity which may cause a
shunt resistance that impares the measur-
ing accuracy.
Type 1 Condenser Microphones
1. Ensure the power is OFF, i.e. the
screen is blank.
2. Insert the CEL-225/3 Preamplifier
into the socket at the top of the
instrument with the key lines on the
preamplifier and nose cone in
alignment.
3. Locate the preamplifier in the keyway
to ensure that the pins are properly
engaged before pushing it into place.
4. Either: Carefully screw a standard
CEL-192 Microphone (supplied) on
to the preamplifier.
Or: Carefully screw an MK-301
Microphone on to the A67 Adaptor
supplied with the microphone and
then screw the adaptor on to the
preamplifier.
SCREW THE MICROPHONE ONLY
FINGER TIGHT. DO NOT USE
PLIERS OR OTHER TOOLS.
Type 1 Electret Microphones -
CEL-250 and MK 250
Warning
DO NOT screw a CEL-250 or
MK 250 Microphone directly
on to the the preamplifier.
The 200 V polarization supply
will DESTROY the micro-
phone (and invalidate the
warranty).
1. Ensure the power is OFF, i.e. the
screen is blank.
2. Insert the CEL-225/3 Preamplifier
into the socket at the top of the
instrument with the key lines on the
preamplifier and nose cone in
alignment.
3. Locate the preamplifier in the keyway
to ensure that the pins are properly
engaged before pushing it into place.
4. Carefully screw the preamplifier end
of the C6601/10 (10 m) Cable on to
the preamplifier.
This cable has the 200 V polarization
supply disabled to avoid destroying
the microphone.
5. Carefully screw the CEL-250 or
MK 250 Microphone on to the
microphone end of the C6601/10
Cable.
SCREW THE MICROPHONE ONLY
FINGER TIGHT. DO NOT USE
PLIERS OR OTHER TOOLS.
6. Support the microphone (with a
CEL-4627 Tripod for example).
General CEL Sound Level Meters Handbook - Page 17