Measuring forces to unravel hair after shampooing - by mounting of comb or brush strain gauges connected in bridge circuit and to counter circuit

摘要

A flexible plastic comb !1) has a metallic plate (2) rivetted to it and which supports a sensor (3) comprising four strain gauges connected in a bridge arrangement. The bridge is powered from a battery (4) connected across one of its diagnols. A cable (5) allows the battery to be located at the counter circuit and also allows the bridge output to be applied to a voltage to frequency converter (7). The output is applied to a pulse counter (8) with a numerical readout (9). The counter reading is proportional to the force required to untangle the hair. This arrangement allows the relative characteristics of different shampoos to be compared.