BRUEL & KJAER 2663, Техническая документация инструкция

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Chapter 2 — Operation
Environment
Preamplifiers Types 2663 and 2663 B
User Manual
Brüel & Kjær
6
2.1 Environment
The preamplifiers have a wide operating temperature range extending from –55
o
C to
+100
o
C (–67
o
F to +212
o
F). It can withstand shock levels up to 100 g (6.5 ms) and
meets the vibration requirements of MIL-STD 810 D, method 514.3, category 6, and is
therefore suitable for vibration measurements on helicopters, all kinds of aircraft,
and in most industrial environments. The preamplifier’s sealing prevents the influx of
dirt and oil and withstands up to 100% humidity, meeting the standards of both the
IEC 58.2.3, and MIL – STD 810D method 514.3 category 6.
2.2 Mounting
The small size of the preamplifiers enables them to be used in relatively confined
spaces where the use of other types of amplifier is restricted. They also have an
advantage in that they can be mounted close to accelerometers, thus eliminating the
need for long input cables which are prone to mechanically induced triboelectric
noise
*
.
The preamplifiers have a 4 mm (~0.15 in.) diameter hole at each corner of their hous-
ing for mounting purposes. They also contain an M 3 Metric Insert for grounding.
Fig.2.1 Mounting of Preamplifier Types 2663 and 2663 B
Ensure the preamplifiers are firmly fastened, where possible, on a vibration-free sur-
face, and that connection cables are properly anchored. The preamplifiers can with-
stand shock levels up to 100 g (6.5 ms) and meet the vibration requirements of MIL –
STD 810 D, method 514.3, category 6. Both preamplifiers’ (individual) mass is
167 grams. They should not be fastened to the vibration test-specimen on which the
accelerometer is mounted, as loading will alter the specimen’s vibration response.
*Triboelectric noise is a spurious electrical output produced by capacitance and dielectric changes in cables
when subject to mechanical excitation