Measuring apparatus with response adjustment

摘要

The output (18) from an optical sensor is recharged for a time dictated by the output of the digital-to-analog converter (11). A previous count indicative of the recharge time is stored in memory (52) which controls the converter (11). This count is manipulated in incrementing circuit elements (54) (70 and 72) depending on the time the comparator (12) signals a difference signal, indicative of a period of recharge.