Process for the control of the physiological state of cellular tissues, in particular for the determination of the freshness and the quality of the fish and device for implementing this process

摘要

1,006,686. Determining physical quantity. J.DETHLOFF. May 10, 1963 .[July 30, 1962], No. 18587/63. Heading G1N. To test the freshness of fish or other animal or vegetable material the impedances at two different frequencies of a part of the material are measured simultaneously or in rapid succession and their ratio is used as an induction of condition. As shown in Fig. 4 two oscillators 0, and 0 2 are connected in series with two electrodes, between which is placed the sample, and a resistor R 3 . The voltage across the resistor R3 is fed to an amplifier V3 and their to separate high and low frequency amplifiers V1 and V2. The output of amplifier V1 is kept constant by feedback through A to the input of amplifier V 3 , the output of amplifier V 2 is also affected by this feedback and thus produces an output proportional to the ratio of the impedances at the two frequencies. Alternatively instead of the feedback path being used the outputs of the two amplifiers may be compared in a cross-field meter if transistor circuit incorporating temperature stabilization and a bridge circuit is described (Figs. 7, 8, 9, 10 not shown). The electrodes may be formed by graphite coatings on the thumb and index finger of an insulating glove. A pair of separate circuits feeding alternately the coil of a cross field meter are described with reference to Fig. 2 (not shown).