GB1487506A - Apparatus for measuring peak values and areas under peaks - Google Patents

Abstract

1487506 Measuring peaks and areas under peaks N I INST INTROSKOPII 5 Dec 1975 49989/75 Heading G1U An arrangement for measuring the peak value of a pulse 107, Fig. 6 of the type in which the contents 111 of a counter, after conversion to analogue form, are repeatedly compared with the instantaneous amplitude of the pulse and the counter is incremented whenever its count is below the pulse, is charactererized in that the increments to the counter are applied either to the stage of lowest significance, or, if the difference between the instantaneous count and the instantaneous amplitude of the pulse is sufficiently large, to a stage of higher significance, thereby causing the count to follow the rising edge of the pulse more closely. As described, the input pulse from an amplifier 2, Fig. 1, is applied direct to a first comparator 4 and via an attenuator to a second comparator 5, each comparator also receiving, from a D/A converter 16, a signal representing the count in a decade counter 13, 14. Whenever the first comparator 4 indicates that the count is below the pulse, a gate 10 is opened to apply clockpulses 12 to the lowest stage 14 of the counter, and if ever the second comparator 5 indicates that the count is below the attenuated pulse a second gate 11 is opened to allow the clockpulses to pass direct to a higher stage 13 of the counter. In a modification Fig. 2, (not shown) the integral of the input pulse is applied to the circuit of Fig. 1 so that the final count represents the area under the pulse, and in a further modification, the clockpulses that form this final count can be routed to a first counter (35) whilst the pulse is rising, and to a second counter (36) whilst it is falling, thereby measuring the area under the rising edge and the area under the trailing edge of the pulse. An appropriate D/A converter Fig. 3, (not shown) using weighted resistors, and a decoding circuit Fig. 4 (not shown) for driving seven-segment display tubes from the binary-coded decimal counters, are described.