GB1334455A - Measuring device - Google Patents

Abstract

1334455 Measuring plastics properties electrically MONSANTO CHEMICALS Ltd 26 May 1972 [17 June 1971] 28505/71 Heading G1N Apparatus for determining the softening point of a thermoplastics sample, i.e. the temperature at which the sample under a given stress deforms by a predetermined amount, comprises a thermocouple t/c which measures the temperature of an oil bath in which the sample is heated, voltage recording means, for example a pen recorder, recording the output of the thermocouple, and a dial gauge G1 sensing the deformation of the sample and provided with electrical contacts which are closed at the desired deformation to operate a relay R1 causing the voltage sensed by the recording means to be reduced to a lower value by a voltage divider D1. As shown, three samples may be sensed cyclically by a motor M driving gauged switches S1, S2. As soon as the appropriate gauge G1, G2, G3, operates its relay the voltage output will be reduced to an amount set by the appropriate divider (e. g. ¢, 1/3, or “) and hence identifying the sample. The graph recorded, Fig. 2 (not shown) indicates the thermocouple outputs at which voltage reductions arise, these being indicative of the softening points. Audio or visible warnings are also envisaged.