FIELD: non-destructive control.
SUBSTANCE: small-sized measuring probe is placed onto thermoplastic material blank. Measuring probe has linear heater (heat source) and thermopiles disposed as on line of action the heater and at preset distances symmetrically at both sides of line of the heater. Then single thermal pulse is generated by linear source and time of relaxation τrel of temperature field and minimal frequency of application of thermal pulses Fmin are determined on the line of influence of the source from the relation of Fmin=l/τrel. After the thermal influence from the heat source is performed by increasing frequency of supply of pulses until speed of heating of tested sample gets the preset value (no more than 1°C per minute). After it the thermopiles disposed at both sides of heater are connected in turn to measuring circuit; first the batteries being the closest to line of action of heater are connected. Thermo-physical characteristics of tested thermoplastic material and speed of heating are calculated on the base of data on temperature-time changes in tested points. As the temperature of sample grows the temperatures are fixed at which temperatures the thermo-physical characteristics change abruptly. Received results are subject to averaging in microprocessor to show them subsequently at indicator screen and put them into on-line storage of microprocessor.
EFFECT: improved efficiency and precision of measurement.
4 dwg, 2 tbl
Authors
Dates
2005-04-20—Published
2004-04-12—Filed