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SUPPLEMENTAL OPERATING GUIDE
MODEL 3085C HIGH TEMPERATURE CHARGE MODE ACCELEROMETER
INTRODUCTION
Model 3085C is a charge mode accelerometer
designed to measure vibration of surfaces at
temperatures up to 500°F. This accelerometer uses an
ultra stable piezoelectric crystal in its self-generating
seismic element.
Model 3085C may be used with various charge
amplifiers of the vibration type (as opposed to the DC
coupled electrostatic types.)
DESCRIPTION
Refer to Outline/Installation drawing 127-3085C.
Model 3085C is packaged in a hermetically
sealed 304L housing and features a transverse
mounted glass-to-metal sealed connector (2-pin, 7/16-
27 UNS-2A shell). The unit is installed by use of (3) 8-
32 x 1/2 inch long socket head cap screws, (supplied).
The mounting screws thread into 3 matching threaded
holes which must be provided in the mounting surface.
INSTALLATION
To mount Model 3085C, it is necessary to drill
and tap 3 equally spaced 8-32 mounting ports on a
1.188 dia. bolt circle. For best high frequency
response, the contact area of the accelerometer must
be selected or prepared to be flat to .001 TIR. The
holes must be drilled perpendicular to the mounting
surface to within 2 degrees of angular error.
After drilling and tapping, clean the area to
remove all traces of cutting oil and machining chips.
Spread a thin layer of silicone grease on the
three contact surfaces of the 3085C. Locate the accel.
over the tapped holes and engage the three mounting
screws through the holes in the flange and into the
tapped holes. Thread the mounting screws into the
tapped holes and torque to 15 pound inches.
Inspect the mating surfaces to ensure that the
accelerometer is snugged down tightly in intimate
contact with the test surface at all three contact points.
If the surfaces appear to be meeting squarely,
the accelerometer is ready for connection of the cable.
INTERCONNECTION
The recommended cable assy for the 3085C is
the Dytran Model 6838A10. This cable is a 10 feet long
with a 2-pin 7/16-27 UNS-2B plug on one end. The
opposite end is terminated cable with no connector.
Connect the cable to the 3085C and connect
the other end of the cable to the charge amplifier.
Apply lock wire if applicable.
MAINTENANCE AND REPAIR
Should you experience a problem with your
system, contact the Dytran factory for technical
assistance in analyzing and trouble shooting the
problem. If the product must be returned for evaluation
and/or repair, you will be given an RMA (returned
materials authorization) number and instructions for
returning the instrument to the factory. Do not return
the instrument without first obtaining this authorization
to return.
SPECIFICATIONS
Refer to performance specification sheet.