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Extendable Borescopes
Lenox Instruments at Work
Some years ago when archaeologists discovered the
tomb of an ancient Egyptian ruler, they wanted detailed,
close-up photographs of the contents. The archaeology
team did not want to disturb the site by opening it up to
admit photographers. The problem was solved with a
Lenox Extendable Borescope, which was inserted
through a hole in the tomb's wall. The photographs
taken through the borescope were so clear and
revealing, they were published by a leading national
magazine.
This is only one of the many different problems that
Lenox borescopes have solved over the years. The first
Lenox borescope, constructed in 1920, was developed
to fill a manufacturer's need for internal visual inspection
of the generator, rotor shafts, and forgings of a steam
turbine.
During World War II, Lenox borescopes came into
common use as the principal means of inspecting gun barrels and artillery pieces. Borescope usage was
expanded by the military during the war to examine formerly inaccessible areas of ships and aircraft. The
first nuclear application arose at the same time, when
Lenox played a part in the secret Manhattan Project.
Not only has Lenox supplied borescopes to the military
from World War II, it has also simplified maintenance
and quality control for numerous industries. Today
Lenox Extendable Borescopes are used to inspect
tubing, vessels & chambers, aircraft landing gear,
radioactive equipment, power generation equipment,
process lines, vats, rocket casings, foundations of dams & structures, helicopters, tank cars, and so much more.
Because of these instruments, complex assemblies at
last may be visually inspected without costly and time
consuming tear downs. |
Selection Guide
To decide which borescope model to order, review the
chart below, and select the scope tube diameter
required for your particular application.
Once you have decided on the diameter, simply read
across the chart to determine the basic working length
of the instrument, the extenders length, and the model
number to be specified. The only additional information
required is your viewing head selection.
To obtain a price quotation, call Lenox at 800-356-1104
or 215-322-9990, or e-mail us at sales@lenoxinst.com.
Please let us know the model number you have selected,
the number of extenders, and which viewing heads you
require. You may also mail your request to:
Lenox Instrument Company, Inc.
265 Andrews Road
Trevose, PA 19053
Scope
Tube
Diameter* |
Basic
Working
Length |
Extender Sections Available |
Maximum
Length* |
Model Number |
35 inches |
35 inches |
31 inches |
10.8 feet |
8F012E |
15/16" (23.8mm) |
28 inches |
3 feet |
44 Feet |
8094-K101 |
1 3/8" (34.9mm) |
53 inches |
5 feet |
59 Feet |
8138K-101 |
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Other Lenox Products and Accessories
Whether you require a standard product or one custom
designed to meet a specific requirement, Lenox can
supply the precise instrument for your R.V.I., Remote
Visual Inspection
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The capabilities of these instruments can be expanded
even further with the use of Lenox accessories including;
video adaptation, photographic attachments (film or
digital), digital recording, centering devices for tube and
pipe inspection, special lenses, and various types of
illumination, including ultraviolet. |
Lenox Extendable Borescope
Although it somewhat resembles a telescope in appearance,
there are some striking differences. A telescope, used for
peering into outer space, is a collector of existing light, focused
on a specific point. A borescope, used for visual inspection of
inner spaces, provides its own illumination and spreads the
field of view. These long tubular instruments consist of the eyepiece
section; this is where the instrument is focused. The objective
section, where the objective lens forms an image of the area
under inspection, and the interchangeable viewing head
section, which provides the illumination and determines the
direction and field of view. Extender sections, added between
the eyepiece and the objective sections, can permit the
borescope to bring an image of an object, up to 100 feet away,
in for a close-up inspection.
In summary: The objective lens forms the image, and is
transmitted through the tube by achromatic relay lenses to the
eyepiece section where it is magnified and the focus adjusted.
Each Lenox Extendable Borescope is free of any mechanical
and/or optical defects, and it is guaranteed to perform the
inspection for which it was designed. It is shipped with an
eyepiece section, objective section, the selective viewing head,
120 volt - 60 Hz variable power supply, a complete instruction
manual, plus the optional extender sections that you purchase.
This is all packaged in a fitted protective case. Power supplies
for 220 volts are available.
Lenox can also provide special magnifications, remotely
controlled scanning, or view arrangements permitting both
visual observation with the ability to snap digital photos, or
viewing and/or recording via a CCTV hook-up. Special
housings are available for severe environments. Tubes can be
designed with angular bends and special deflections or offsets.
Optical systems are available for ultra violet inspections,
resistance to nuclear radiation or for topographic inspection to
measure depths or size of defects. Viewing heads can be
engineered to meet virtually every type of observation
requirement.
Many considerations are involved in borescope design,
such as magnification, water sealing, condensation,
temperature extremes, field of view, light transmission,
nuclear radiation, angular bends, deflections of the tube,
explosion proofing, and correction of aberrations. It is in
these considerations that the experience Lenox has
acquired through the years, in designing thousands of
systems, is best demonstrated.
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Mechanical Design
Lenox borescopes are designed to permit complete
disassembly for cleaning or modification to satisfy future
applications. Scopes under one inch diameter are
constructed from hard-drawn stainless steel tubing, while
larger diameter borescopes utilize aluminum tubing. Their
sturdy construction enables them to withstand the use, and
abuse, to which they are subjected in the typical industrial
setting. Although these borescopes may be used in
laboratory work, they have been designed and constructed
for rugged industrial applications. |
Electrical System
Instruments are internally wired to conduct current to the
lamps in the heads. Special attention is given to the type of
insulation used. Lamps are of the highest quality available,
and offer a long operating life. In most cases these lamps
are commercially available. Although these borescopes
usually operate from a variable power supply, battery units
can be supplied for remote operations. |
(A) The Eyepiece Section
The eyepiece
section includes the eyepiece, electrical connection,
eyepiece optical system, and handwheel.
The eyepiece is interchangeable, and has an adjustable
focus. The electrical connection revolves, permitting the cable
to swing freely without tangling as the instrument is rotated to
view from a different angle. In order to rotate or otherwise
direct the borescope, the operator simply uses the hand
wheel as a steering wheel.
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(B) The Objective Section
This section contains the objective lens, and the built-in
achromatic relay lens. The objective lens matches the
required field of view, which spreads the image so that a
large area may be seen at one focus setting.
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(C) The Viewing Head Section
The viewing heads are all interchangeable, and each
provides its own direction of view, as discussed further on.
The head contains the lamp which illuminates the object
being inspected with adjustable high intensity light. A mirror or
prism assembly is included in all heads, with the
exception of the bottoming head, to provide the desired
direction of view.
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The Extender Sections
Extenders are threaded tubes containing achromatic relay
lenses. These sections extend the working length of the
borescope. Working length is the basic reach of the
instrument between the hand wheel and the objective lens in
the objective section. The basic working length of the
sectional scope does not include extenders. Each extender
section increases the actual working length by its own length
until the maximum length is achieved
Extenders are available in 3 of 5 foot sections, depending
on the model selected. |
Viewing Head Options
Many types of mirror and prism arrangements are available
to direct the "cone of view" as required. Most needs,
however, can be met by using one or more of the standard
interchangeable viewing heads depicted and depicted and
described below.
Each viewing head provides maximum illumination under
normal conditions where at least medium contrast exists
between the object to be inspected and its surrounding
background. If required, even brighter illumination can be
provided. |
Right Angle
This is the most frequently used viewing angle. The viewing head bends the "cone of
view" at right angles to the borescope axis, providing a lateral view. It is generally used
for the more critical inspections or to cover certain areas.
Circumference (Panoramic)
This head is designed for rapid inspection of tubing or other cylindrical shaped
structures. It projects forward to view the wall at a slanting incidence so a 360 degree
band, several nches wide is seen at a glance. A centrally located mirror provides a
right angle view for a critical study of the area just scanned by the panoramic view.
Bottoming
Provides a "cone of view" directly forward and has uniform circumference illumination
permitting careful examination of facing walls or bottom of blind holes or cavities.
Retrospective
The "cone of view" is at a retro angle to the borescope axis, providing a view of the
area that was just passed by the advancing borescope. Ideal for viewing inside the
neck of cylinders and bottles.
Forward Oblique
The "cone of view" is at a forward oblique angle to the borescope axis, enabling the
user to view the corners at the far end of the cavity or bore.
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