vided for each channel for adjusting the channel gain
for the type of transducer being used. A self-
generated calibration signal provides a means for
calibrating each channel individually. The output of
the selected channel is normally read directly on the
meter. The front panel contains an indicating meter
and the primary operating controls. Four sensitivity
controls are located behind an access door near the
bottom of the front panel. An electrical connector is
provided on the front panel for connecting an oscillo-
scope to the vibration meter output circuit. The rear
panel contains four channel input connectors, an
input power fuse, and connectors for connecting an
external remote meter and a galvanometers to the
vibration meter output circuit. A six-foot long ac
power cord is permanently attached to the vibration
meter. This cord is stored in a recessed section of
the rear panel as shown in figures 1-3 and 1-4.
1-7. VELOCITY VIBRATION TRANSDUCER ASSEM-
BLY, Type 4-128-0101. (See figure 1-5.) The velocity
vibration transducer is a linear, self-generating unit
that produces a voltage output proportional to vibra-
tional velocity. Measurements of vibratory motion is
Top View, Cover Removed
accomplished by using the seismic mass principle.
The transducer measures vibrations of from 15 to
per second). Additional equipment may be included in
1500 cps, and is designed for use with the Type
the system for further examination or for recording,
1-117-0105 Vibration Meter. The transducer con-
as shown in figure 1-2.
verts mechanical vibrations into ac voltage signals
1-4. PHYSICAL DESCRIPTION.
which are proportional to the velocity of vibration.
1-5. The vibration test kit consists of one vibration
1-8. CABLE ASSEMBLIES AND CABLE REELS. The
meter, three vibration transducers, five cable assem-
vibration monitoring kit includes three 300-inch cables
blies mounted on five cable reels, eight different
(Part No. 49657-300) and two 900-inch cables (Part
types of adapters and brackets for mounting the
No. 49657-900) wound on five cable reels (Part Nos.
transducers on the aircraft engine, and an ac ground-
ing plug adapter. All components are contained in a
hermetically sealed, aluminum carrying case for
maximum protection from outside environment. Each
component fits into an individual cutout of a molded
animal hair cushion support where they are further
protected against vibration and shock. The carrying
case has two handles on each end, and is secured
closed by six latches. A relief valve is included to
equalize the pressure inside the case. The carrying
case conforms to Specifications MIL-C-4150E, MIL-
T-945A, and MIL-STD-108D Class I.
1-6. VIBRATION METER TYPE 1-117-0105. (See
able precision instrument consisting of a chassis
assembly and case assembly. The chassis assembly
consists of a chassis suspended between a front panel
and a rear panel. The instrument provides four input
channels. Each channel will accommodate any self-
generating transducer with characteristics compatible
with the vibration meter. A sensitivity control is pro-
