Liq. e.g. blood change of state detector - measures cyclic variation in electrical resistance as agitator rotates

摘要

The liquid or semi liquid such as blood changes its state when it coagulates. Such changes are detected by measuring cyclic variations in electrical resistance produced by rotation of an agitator. The liquid under investigation is contained in a receptical (1) of electrically non conducting material. Two electrodes (4) in the base (3) are connected (5) to a constant current generator (6). An agitator (7) is driven via a magnetic bar (17) on electrical motor (16) with reduction gearing. A detector cell (18) measures resistivity of electrical circuit through electrodes and liquid and depends on position of bar (11) an agitator base w.r.t. electrodes. A signal conditioning circuit (19) determines variations of resistivity.