Precision encoder for micro-measurement

Precision encoder for micro-measurement

Precision encoder for micro-measurement

A measuring resolution of 10 nanometres (nm) is now achievable with the latest Heidenhain PP201R incremental two-co-ordinate encoder. The device has been developed for specific application of measuring and positioning such as found in the high speed world of automation typical of the semiconductor industry.

A measuring resolution of 10mm is now achievable with Heidenhain's PP201R encoder

Now available from Heidenhain (GB) of Burgess Hill in West Sussex, the 98mm square PP201R encoder provides a measuring range of 68mm x 68mm and can be applied at traverse speeds up to 30metres/min.

Two main components comprise the new encoder, namely a grid plate and a scanning head. The grid plate has a regular square grid pattern applied to a glass substrate at 45° to the direction of measurement. Each square has edge length of 2.83 microns which has the effect of creating a grating period, in either measuring direction, of eight microns. A reference mark for each axis extends perpendicular to the measuring direction over the entire measuring length which simplifies the setting of a datum.

The non-contact scanning head functions according to the interferential measuring principle. Each scanning sensor generates two, 90° phase-shifted sinusoidal output signals with a signal period of four microns and one reference mark signal. Electronic interpolation of the output, taken from each measuring direction, supplies measurement to the quoted resolution.

The scanning head incorporates an APE interface unit and the device is supplied with connection cable for each measuring direction. Separate adaptor cables can be obtained, in a variety of lengths, for onward connection to subsequent electronics.

Contact Mr Michael Laming, Commercial Manager, Heidenhain (GB) Limited, 200 London Road, Burgess Hill, West Sussex RH15 9RD. Tel: 01444 247711.