Ships' Technical Manual for specific care and
maintenance information.
ULTRAVIOLET TEST UNIT
The ultraviolet (UV) test unit is a battery-
operated unit that outputs an ultraviolet light
beam to test the ultraviolet light flame detectors.
The test unit is a cylindrical object. It has a pistol
type of grip that contains a trigger to control the
unit attached to the bottom side of the cylinder.
HEAT GUN
The heat gun is a device that outputs forced
hot air. This is used to test the temperature
detectors in the gas turbine enclosure. The heat
gun looks and works on the same principle as a
blow dryer.
STROBOSCOPE
The stroboscope is an instrument that permits
rotating or reciprocating objects to be viewed inter-
mittently and produce the optical effect of slowing
down or stopping motion. For example, electric
fan blades revolving at 1,800 rpm will apparently
be stationary if viewed under a light that flashes
uniformly 1,800 times per minute. At 1,799
flashes per minute, the blades will appear to rotate
forward at 1 rpm, and at 1,801 flashes per minute,
they will appear to rotate backward at 1 rpm.
The strobotac (fig. 3-25) is an electronic flash
device that has a very short flash duration (on the
order of a few millionths of a second). This allows
very rapid motion to be stopped. The strobotac
Figure 3-25.--Strobotac.
box contains a swivel mount with a strobotron
lamp in a parabolic reflector, an electronic pulse
generator that controls the flashing rate, and a
Function of the Borescope
power supply that operates from the ac power
line. The flashing rate is controlled by the large
The word borescope is made up of two words.
knob. The corresponding speed in rpm is indicated
These are bore, which means cylindrical cavity
on an illuminated dial viewed through windows
(such as in the case of a hydraulic cylinder or gun
in the knob.
barrel), and scope, which means to observe. In
the borescope application of inspecting the gas
BORESCOPE
path components of GTEs, the majority of the
observing to be done is at some angle relative to
The borescope is an instrument used to inspect
the axis of the borescope inspection hole (port).
the internal parts of the GTE. Inspection is
You can think of the borescope as a type of
performed by passing a fiber optic probe (rigid
periscope.
or flexible) through parts in the engine. This
This periscope would be a simple device if it
allows the operator to view the engine parts in the
were not for the need to illuminate the object
gas flow path.
observed. In the equipment described in this
3-17
