SPI Interferometers for visual flatness check of precision parts

Lamtech Lasermesstechnik offers interferometers for visual flatness check of finish-machined  parts.

In order to evaluate the test object, the part is placed on the glass surface of the SPI. Part and fringes are than presented enlarged on the video monitor. The evaluation of the flatness happens on the basis of interpretation of the straightness, parallelism and equidistance of the interference fringes shown on the monitor.

The interferometers are suitable to be placed in the production area close to the processing machines.

The Program INTDOK (more) or a video printer enable the documentation of the flatness of parts.

Visual inspection interferometer SPI – for visual flatness check of finish-machined surfaces

SPI visual inspection instruments allow the flatness check of lapped, ground or polished surfaces. Like the TOPOS flatness measurement instrument, the SPI interferometer is also based on the principle of grazing incidence of light. Thus, with the SPI interference fringes are visible with matte test objects. The part does not have to be polished before the examination with the SPI.

SPIs are available with a measuring field of 75 and 130mm.

Additionally, we offer the SPI-xs with enhanced sensitivity. The sensitivity is set up to 0.3 µm/fringe, which corresponds to the sensitivity of the measurement with an optical flat and a helium or sodium lamp.


sensitivity measurement standard

Optional a sensitivity-standard is provided, which is used for the routine control of the correct sensitivity setting of the SPI Visual Inspection Interferometer

SPI brochure (PDF, 270 kB)

Would you like to receive further information, download here the latest brochure of the SPI.