Automatic measurement of areas.

摘要

The invention provides an apparatus for determining the size of a test piece (10) comprising means to support the test piece (10) in a predetermined position, means (S) to direct a medium onto the test piece (10), means (11) responsive to said medium to provide a signal (30) which varies in accordance with variations in intensity of said medium reflected from or transmitted from or past the test piece (10), electrical processing means (12) to process the signal (30) to provide an output (0) dependent upon the size of the test piece (I) which can be interpreted to determine the size of the test piece (I).