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SIAM - Secondary Image Angle Measuring Instrument


The Secondary Image Angle Measuring Instrument (SIAM) is a measuring device for the determination of angles between primary and secondary images for windshields. It is very useful in positioning Heads Up Displays (HUD's).


SIAM - Secondary Image Angle Measuring Instrument


SIAM - Secondary Image Angle Measuring Instrument


The included software allows the automatic determination of the angle as well as the recording of the angle together with its measuring position on the windshield. The instrument uses a collimated laser as a source, and a telescope equipped with a log sensitivity camera as a detector. This allows the primary and secondary image, which differ in intensity by several orders of magnitude, to both be detected on the same camera without over saturating the image. The instrument works in compliance with ECE R43. For more information regarding this compliance, please view the presentation available below in the downloads section.


  • No disturbance by local refractive index and power variations due to small diameter of the test beam

  • Easy and fast set-up of the instrument

  • Laser is eyesafe

  • Measurement value is independent of the distance between laser, windshield and telescope

  • Objective measurement results due to PC-based image evaluation software

Technical Data


Description:                   SIAM (Secondary Image Angle Measuring Device)

Art. No.:                          237 503

Measuring range:         60 x 48 arcmin


uncertainty:                   0.5 arcmin

Laser:                               He-Ne-laser with 632.8 nm wavelength (laser safety class 2)

Scope of delivery:         Laser, telescope with camera, adjustable holder D65, lifting table, evaluation software SIAM

Optional accessories:  Tripod stand (Art. No. 223 083)test-wedge, 8 arcmin, D80 (Art. No. 237 508)

Patent:                             US 9,759,671 B2


Software Features


  • Real-time evaluation with 25 Hz frame rate

  • Automatic brightness control

  • Evaluation according to ECE R43

  • Display of the double image angle with magnitude and direction

  • Use of predefined customizable measurement templates

  • Generation of protocol (PDF or ODT)

  • Export of measurement results to spreadsheet software (CSV-format)

  • Transmission of the measurement results via network interface



SIAM - Secondary Image Angle

Measuring Instrument:

Datasheet & Presentation Downloads

Click on the PDF icons to view, print or download the documents.

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SIAM Datasheet

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SIAM Presentation

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