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Warren-Knight Electronic Observation Theodolites 20-9000 Series

Warren-Knight corporation of Philadelphia PA. USA has over 100 years of precision optical instrument experience.   They have been manufacturing pilot balloon theodolites for over 40 years.    While the time tested 20-84xx mechanical pilot balloon theodolites are still available, the versatile 20-9xxx series are fully modern "State of the Art" instruments.

The models 20-9xxx are a series of Electronic Observation Theodolites with RS232 connectivity.  They are available in a myriad of custom configurations.  Options including encoder types, optical plummet, compass, erect or inverting image telescope, dual displays, manually readable circles, heaters, and illumination can be configured to customer requirements. 

The Model 20-9103 is pictured below left.   It a high accuracy model that was designed to support alignment of ILS systems, and other high accuracy uses in addition to pilot balloon use.  The model 20-9103 has the same optical and mechanical tracking system as a manual theodolite (a user familiar with previous models will have no trouble operating it).   This model improves on previous generations by adding an LCD display and an RS232 serial data interface.  The angular presentation is user selectable to show degrees minutes and seconds with a resolution of 10 arc seconds, or decimal equivalent with a resolution of .001 degrees.  This instrument has been designed to accept motor drives and worm driven potentiometer and encoders, allowing new electronic theodolites to work with existing systems using the older theodolite configurations popular throughout the world.

The Model 20-9628 (visually identical to the 20-9568*) is pictured below right.  These theodolites are a completely new platform, where as the 20-9103 is an incremental digital design. This is a more modern series that incorporates many desirable improvements to balloon theodolite design.  It has the 0.1 degree (6 arc minute) digital resolution* requisite for pilot balloon studies.      The 20-9628/20-9568 have the following design improvements over the older David White, Warren-Knight theodolite designs. 

  1. Glass etched reticule - replaces delicate spider web (has open center so distant balloon is not lost in cross)
  2. 3 level LED lighting - replaces white incandescent lamps (less chance of eye night vision loss).
  3. Friction drive worm gears - replace positively engaging worm drives (Not needed because system does not require micrometers)
  4. SWNG mode which automatically adjusts output when tracking an object that passes overhead.  (maintains elevation between 0 and 90 degrees and adjusts azimuth output accordingly). 
  5. More robust peep sight than the fragile gun sites of older models
  6. Lighter and more compact.
  7. * Model 20-9528 has a similar excellent optical circle readout system which is viewable through main eyepiece that the Soviet produced mechanical theodolites pioneered and the 20-9528 has addition of digital electronics.  This system can be read to 0.05 degrees (3 arc minutes).   The theodolite can be operated visually without power to the electronics.   

 

image Warren-Knight 20-9105 balloon theodolitePhoto of a Warren Knight 20-9628 pilot balloon Theodolite

 

For more information contact Richard Marron at Warren-Knight
Warren Industries Incorporated
2045 Bennett Road - Philadelphia, PA 19116
Phone: 215.464.9300 - Fax: 215.464.9303

rmarron@warrenind.com
http://www.warrenind.com/thedo.htm