optical design, engineering
& manufacturing |
Clearly Your
Choice for
PRECISION OPTICS |
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Test
Glass Pricing |
| Specifications:
Master test glasses are made in plus (convex) and minus
(concave) pairs. Our primary method for measuring radius is with the
Zygo ZMI-1000 (Zygo Interferometric Radius Scale), which has a
resolution of .0000025mm, and represents the state of the art in
radius measuring systems, commercially available today. Surface
irregularity (sphericity) is measured with a Zygo GPI XPS (phase
measuring interferometer system) and also the "fit" of the two halves
are checked with the parts in contact under monochromatic lights. For
shorter radii, the convex element is usually made as a hyperhemisphere,
which aids manufacture and allows a convenient check on the radius by
direct measure of the ball diameter. For production lens runs, working
test glasses, slightly larger than the lenses, are usually made to
avoid wear on the masters. |
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Tolerances: Standard surface irregularity, 1/10
wave or better. Standard radius tolerance, 1/20 of 1 percent for radii
between 5 and 750mm (provided the ratio of diameter to radius is
reasonably large). Much tighter radius tolerances than this can
normally be achieved at little or no additional cost. Certification,
traceable to NIST, included with all master test glasses. Surface
quality (scratch-dig) is 120-80 where the scratch width is specified
in microns, except that light grey, under inspection method 4.2.2.1 of
MIL-0-13830A, is acceptable. |
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Hyperhemispheres
(Concave element to approx. 80% of a hemisphere) |
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1.500 to 2.999mm radius |
$475.00 |
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3.000 to 19.999mm radius |
$398.00 |
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20.000 to 24.999mm radius |
$460.00 |
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25.000 to 30.000mm radius |
$520.00 |
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Other Master Test Glass Pairs |
|
Diameter (inches) |
Radius (mm) |
Price Per Set |
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| 1.75 and less |
25.00 and up |
$450.00 |
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2.00 and 2.25 |
40.00 and up |
$470.00 |
| 2.50 and 2.75 |
60.00 and up |
$510.00 |
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3.00 and 3.25 |
80.00 and up |
$545.00 |
| 3.50 |
90.00 and up |
$595.00 |
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4.00 |
110.0 and up |
$675.00 |
| 5.00 |
160.0 and up |
$910.00 |
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6.00 |
220.0 and up |
$1200.00 |
| 7.00 |
400 and up |
$2150.00 |
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Working Test
Glass
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| (“Working”
test glasses are single test glasses which are matched to an existing
master or made along with a set of masters.)
Tolerances: Production test glasses are
pitch polished to 1/10 wave regularity. Accuracy of 1/20 wave can be
achieved on request. Radius matched to 1/4-wave fit to the master test
glass. Prices: Prices are for a single test glass when purchased with
a set of masters. Add 20% for test glasses made to your master.
Discount 10% on each additional test glass of the same radius. |
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Diameter (inches) |
Price Each
(If made along with masters
of the same radius.) |
Price Each
(If made to match your existing
master or a master from our inventory.) |
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| 1.75 and less |
$190.00 |
$250.00 |
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2.00 and 2.25 |
$200.00 |
$260.00 |
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| 2.50 and 2.75 |
$215.00 |
$280.00 |
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3.00 and 3.25 |
$245.00 |
$300.00 |
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| 3.50 |
$260.00 |
$325.00 |
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4.00 |
$300.00 |
$375.00 |
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| 5.00 |
$400.00 |
$500.00 |
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6.00 |
$540.00 |
$660.00 |
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Materials: All test glasses made from
precision annealed Pyrex. Prices available on request for other
materials, larger diameters, or special specifications. A 15%
reduction in price will be allowed for a tolerance of 1/4 wave
irregularity and 1/2 wave fit. Interferometric testing (Zygo GPI and
distance measuring interferometer) of both radius and irregularity
available in house. Terms: 1%-10, Net 30 (with established credit);
F.O.B. McHenry, Illinois. |
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© 2007 Kreischer Optics, Ltd. Revised April 2004 -
Price subject to change without notice.
Kreischer Optics - 1729 Oak Drive -
McHerny, IL 60050 - phone:
(815) 344-4220
/ email: optics@kreischer.com
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