PC-controlled Comparison Goniometer

Comparison Goniometer

The system includes an autocollimator mounted on a stand with a swivel arm and a collimator in the ground plate. The auto-collimator image is taken by a CCD-camera and further processed via frame grabber, PC and specific software. Measurements are made in reflection for outer prism angles and in transmission for internal deviation angles.

The PC-controlled Comparison Goniometer features high accuracy and extremely short measurement time . A prism measurement takes just the time to press a key of the PC. Being accurate, extremely fast and non-expensive, the Comparison Goniometer is perfectly suited for production environment and larger quantities of pieces.

Stand with Swivel Arm

The stand is equipped with a handwheel for convenient and quick swiveling of the arm with the autocollimator holder. On the left side a locking lever allows for fixing the autocollimator in a position nearly square to the prism surface to be checked. A disk placed in the front of the swivel axis and divided in degrees helps finding the desired angular position .

A knob placed on the right upper side of the stand enables the accurate fine adjustment with arcsec sensitivity. A second lever is used to lock the arm with the autocollimator in a stable working position.

The sample to be measured is placed on a combination tilt and rotary table with fine   adjustment facilities. To accommodate different sample sizes this assembly can be adjusted in the highs and locked in the working position.

The sample to be measured is placed on a combination tilt and rotary table with fine   adjustment facilities. To accommodate different sample sizes this assembly can be adjusted in the highs and locked in the working position.

A device with interchangeable 3 ball supports of different sizes is firmly fixed on the table. The positioning of the samples on the 3 ball supports ensures the necessary repeatability. This device has in addition a mount where a mirror could be firmly mounted for measurement in transmission (double pass) of parallel plates or wedges with small angles.

In the stand base is mounted a collimator with deflection mirror at 45° for measurement of internal angle deviation through prisms (e.g. pentaprisms).

The autocollimator and collimator are interchangeable so that the required focal length or aperture can be selected according to the requirements (accuracy, field of view, eta) of the measurement.


The Comparison Goniometer can be used for angle measurements of any piano optics in production quantities with high speed and consistent accuracy:

  • any prism angles
  • wedge angle
  • 90°-angle of prisms
  • parallelism of plane plates
  • deviation angle through wedges and prisms
  • pentaprisms angle
  • mirror tilt

Advanced Software

The user-oriented software has been developed to really meet the requirements of an easy, quick and errorless measurement:

  • the software package runs under Windows 95 or WINDOWS NT in German and English. The measurement results can be displayed in different units: arcsec, arcmin, urad.
  • real time monitor display of the autocollimator image
  • it enables the measurement of small or anti-reflex coated samples
  • it features automatic measurement sequence with free selectable parameters
  • extremely fast measurement: 1 sec.
  • high reproducibility of the measurement results irrespective of the operator’s qualification
  • measurement of high speed rotating mirrors or disks
  • it provides a statistic evaluation of the measurements including mean value and standard deviation.
  • automatic calibration procedure by means of a calibrated sample. The calibration can be checked at customer site
  • certificate of measurement can be stored or printed out
  • storage, loading or export of files for further processing



Swivel range: 0°-90° left side, 90°- 45° right side

Dimensions and weight: height: 450 mm, stand base: 350×350 mm, weight: approx. 25 kg

Tilt and rotation table: diameter 100mm, tilt ±2°, rotation 360°/±2.5°, sensitivity 5 arcsec


Measuring Range: 0° – 360°

Master prism: required (except 90° angle)

Standard equipment: ACM 300-57, COL 150-38

Resolution: 0.1 arcsec

Accuracy: +/-1 arcsec (with ACM 500)

Measurement Mode: Reflection and Transmission

Ordering Information

GONIOMETER, complete, incl. stand, ACM 300-57, COL 150-38, CCD-camera, camera adapter, tilt and rotation table, software and framegrabber board, cold light fiber optics illumination, mirror dia. 36mm.

Calibration wedge, accuracy +/-1 arcsec

Support base to be mounted on table

3 ball support D 10mm

3-300- 113
3 ball support D 25mm

3 ball support D 50mm

3 ball support D 75mm

On request the goniometer can be equipped with other autocollimators/collimators depending on specific applications.

Masterprisms are also available on request.