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ENCODER DISKS
DRC replicates masters that have been generated using
advanced numerically controlled techniques to create our Rotary Encoder
Discs. Environmental conditions have been stringently controlled with
seismic isolation equipment, temperature uniformity of 0.1 degree
Fahrenheit, and humidity controls.
Functional Testing
DRC has designed and built a testing device for checking
transmission variation in code discs.
D.C. Testing variation in transmission or "D.C.
Swing" is defined as follows: The maximum variation in transmission
measured at the radial center of the code pattern, and protected around
the entire pattern (360 degrees) to be 3% - 10%. (The actual transmission
specification assigned is a function of line count, diameter, customer
requirements, and manufacturing technique i.e., photo-emulsion or
Metrifilm.)
The output data is in graphic form and therefore becomes a
permanent record to remain with the disc until final assembly.
The test is "standard procedure" for discs
produced at Metrigraphics. A copy of the transmission graph can be
included with each disc upon request.
The correlation of data gained in this test, and the
performance of discs in customer applications has been found to be very
high.
Harmonic Testing
Harmonic error testing by use of a flutter meter is a
means whereby signal output from a rotating disc is compared to a stable
frequency. It is essential to the method that the rotating speed be
extremely uniform. To that end, we have developed a sophisticated
air-bearing spindle. This spindle, which is mounted in an eight-inch thick
granite surface plate, reduces systematic errors and allows direct
identification of disc errors.
Major advantages of the system are that harmonic error
components can be isolated (by frequency selection) and measured directly
in a manner, which closely approximates customer applications. Disc error
identification to better than 1 arc/second is achievable.
View our Standard
Incremental Discs brochure (size: .29 MB, pdf format)
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