OptiCentric^® Accessories

The following accessories are offered to extend the use of OptiCentric^® instruments.

Motorized Centering and Cementing Equippment with vacuum chuck

Extension of Measurement Range

Measurement Sensor and Linear Measuring Gauge

Alignment Set

Illumination

Revolving Turret

Calibration Tool

Motorized Centering and Cementing Equipment with Vacuum Chuck

The vacuum unit is a rotation device to measure the centering error of single lenses with the outer edge as the reference. The lens is rotated using a motor-driven friction wheel against a V-block. The lens is held in position by vacuum.
The control of all functions such as the pressure, rotational speed and vacuum pump is integrated in one control unit. A compressed air line system is not required. The vacuum rotation fixture exhibits an excellent level of accuracy and reproducibility. Possible errors relating to the roughness of the outer cylinder are averaged out so that the results have a very high repeatability.

The maximum sample diameter for measurements with the standard vacuum unit is 75 mm. A modified unit for measuring samples up to 210 mm diameter is available.

The vacuum unit is the standard tool of OptiCentric^® MAN instruments but may be purchased as an accessory for OptiCentric^® MOT to enable lens cementing using OptiCentric^® MOT.

Extension of Measurement Range

Measuring range of the OptiCentric^® system is limited by the size of the upper surface radius when measuring in reflection mode or the effective focal length when measuring in transmission mode. TRIOPTICS provides a set of additional head lenses to extend the range of radius and focal length up to +/- 2000 mm. On request special lenses can be provided for larger values. Plano surfaces (radius = ∞) can be measured at any time with the bare autocollimator using the parallel optical path by removing the head lenses.

Measuring Sensor and Linear Measuring Gauge

On request different mechanical measuring gauges are supplied with the OptiCentric^® instrument. Following gauges are available:

• A gauge for the linear stage of the measurement head to measure its position with +/-2 μm accuracy. The length of the linear measuring scale is aligned with the track of the OptiCentric^® system. This gauge is required for precision measurement of radius of curvature or thickness.
• A lever gauge (Force 0.02 N, measurement range of 0.6 mm, repeatability 0.1 μm) is used to measure or align sample housings with respect to the axis of rotation.
• A mechanical gauge with absolute accuracy of 0.2 μm and measurement range of 25 mm. It is used for alignment purposes, too.

Alignment Set

In order to align sample holders or directly adjust the sample barrel and housing, a set with two high-precision parallel flats (25 and 50 mm diameter) and two glass balls with diameters of 4-12 mm and 14-28 mm is offered.

Illumination

Every OptiCentric^® system is provided with a suitable light source. This is usually a 150 W halogen cold-light source with a 1 m optical fibre light guide. All TRIOPTICS autocollimators and collimators are fitted with a standard interface for the illumination so that various light sources can be exchanged for one another. The following light sources are available:

• 150 W cold-light source with light guide
• 250 W cold-light source with light guide
• 20 W halogen lamp mounted directly on the autocollimator lighting assembly for increased IR output
• 5 W filament bulb
• 100 and 300 mW high-power light emitting diodes (LED)

Every collimator and autocollimator is also fitted with a spectral filter. Depending on the application a green or white light filter is applied.

Revolving Turret

The turret is recommended for the quick and simple change of the head lenses. OptiCentric^® offers a manual 4x changer and a motorized 6x changer. On request both changers can be supplied assemblied on the measuring head.

Calibration Tool

TRIOPTICS offers calibration wedges for the regular inspection of the measurement accuracy of the OptiCentric^® system. The certified wedge angle is traceable back to international standards. The wedge angle is certified to an accuracy of 1 arcsecond.