D-638 COORDINATE AUTOCOLLIMATOR
- Two axis capability
- Compact folded design makes alignment easy
- Built-in adjustable mounting base
- Center tilted eyepiece for easy viewing
- Dark field projected reticle and external readout reduce eye fatigue
- Certification of accuracy traceable to NIST
Operating ease and convenience are built into the Model D-638 Coordinate Autocollimator. The midsection turret with tilting eyepiece and the adjoining, easily read micrometer drum enables the technician to take more readings with less effort. Hand adjustments of the mirrors in the line of sight is brought approximately 10 inches closer to the viewer so that you can stand normally and comfortably.
The D-638 measures angles around an X-Y axis or intermediate points between obliquely tilted surfaces. By rotating the turret assembly 90° the filar bisection of the target gives a corresponding read-out in arc minutes and seconds on the adjoining micrometer drum, either for azimuth or elevation. Azimuth and elevation adjustment are quickly made with fine thread adjustment screws mounted in base.
The Digital Autocollimator Upgrade Kit allows existing D-638 models to have all the digital functionality of the New Model D-720, Digital Two-Axis Autocollimator.
The upgrade kit replaces the autocollimator eyepiece assembly with a video imager. The included OptiAngle software allows results to be viewed in real-time, statistically analyzed and stored for later reference. The program includes routines for the measurements of angles about orthogonal axes, optical wedges, 90º prism errors, telescope angles and more. Certificates documenting test results are automatically generated.
The basic function of an autocollimator is to detect and measure a deviation in the position of a reference reflective surface. The autocollimator projects a collimated beam of light onto a reflective surface. When a deviation in the position of that reflective surface occurs, a deviated beam of collimated light returns to the autocollimator. A direct angular reading autocollimator, such as the Model D-638 Coordinate Autocollimator or the Model D-656 Two Axis Autocollimator, will provide a direct angular measurement of the reflective surface deviation through acquisition and measurement of the deviated return beam angle.
For more theory of operation, please refer to the Principles of Autocollimation Application Note.
|Sensitivity:||0.1 arc sec (standard deviation 0.2 arc sec)|
|Accuracy:||0.5 arc sec over 1 arc min, 3 arc sec over 20 arc min
(Calibration curve over full range available at nominal cost)
|Measuring range:||20 arc min graduations 0.2 arc sec|
@ long distances:
|±10 arc min at 30 ft (9.1 m)
±2 arc min at 125 ft (38.1 m)
|Arc seconds scale:||One revolution equals one minute|
|Arc minutes scale:||Counts revolutions of arc sec scale; graduated from 0 through 20 arc min|
|Aperture Diameter:||2.375 inch (60.3 mm)|
|Eyepiece Magnification:||12X (24X available)|
|Focal Length:||20 inch (508 mm)|
|Projected Reticle:||Dark field with illuminated concentric circles approximately 2 arc minutes apart around an approximately 10 arc sec diameter center dot|
|Light Source:||Incandescent lamp with D-416, 6 VDC variable power supply 110V/ 60Hz or 220V/ 50Hz|
|Overall Dimensions:||Height:||9 inch (229 mm)|
|Width:||6 inch (152 mm)|
|Length:||12.5 inch (318 mm)|
|Base Length:||10.5 inch (267 mm)|
|Height to Aperture Center:||3 inch (76 mm)|
|Weight:||21 lbs (9.5 kg)|
|Shipping Weight:||40 lbs (18.1 kg)|
Model D-165 High Intensity Light Source. This option may be required when autocollimating off of low reflectivity surfaces or small mirrors.
Model D-247 Table Instrument Stand
Model D-416B 220V 50Hz Power Supply
104-0160-638 Autocollimator Alignment Aide
104-0170-638 Digital Autocollimator Upgrade (for existing D-638’s)
105-2761-638 Video Camera & Monitor with integral camera power supply. With this option readings become very easy even for unskilled personnel. Repeat readings are more accurate and faster. The camera eliminates any errors from parallax and greatly reduces eye fatigue. This option is easily added to existing Model D-638's