Abstract: To characterize an object (3) to be measured, for example to gauge the thickness (d7) of a layer (7) borne by a substrate (4), an ultrasonic wave (8.1) is transmitted by a measuring device (1). Echo impulses (8.2, 8.5) reflected by boundary surfaces (5, 10) of the object (3) to be measured are detected by the measuring device (1); the measuring signal is digitalised and subjected to an evolution analysis in the time domain. The evolution analysis uses an algorithm which is computation-efficient by orthogonalisation and implemented search strategy. The characteristics of the object to be measured, for example the thicknesses, are determined from the delay time differences of the echo waves (8.2, 3.5).

Abstract: Echo canceler. A circuit arrangement for the cancellation of echo signals, wherein in the received path, an analog/digital converter is connected with a first adder and a second adder is interposed after the analog/digital converter, with the estimated echo signal being divided into first and second portions, whereby the first portion is transmitted to the first adder and the second portion is transmitted to the second adder for the production of the received signal. In a further embodiment, a third adder is interposed between the analog/digital converter and the second adder, via which the output signal of a compensation filter is added to the signal in the received path.

Abstract: A discrete, precut strip, lead frame plating system wherein each strip is loaded onto a linked chain, located against plating masks, contacted electrically, plated, dried, and unloaded from the chain in successive sequential fashion.