Determining solidification curve of resins and adhesives - using dielectric spectroscopy with sample under test between electrodes of capacitor subjected to AC electric field to measure frequency dependent AC resistance

摘要

The hardness condition of the resin or the adhesive is obtained by determining that alternating frequency, which effects a specified relationship of ohmic resistance and capacitive resistance. The actual measured value of the ohmic and capacitive resistance are derived for the reprodn. of the alternating field frequency. The measurement system has a function generator (F) for the control, and a sensor (S) with two coplanar meshing electrodes (KE) with mutually meshing teeth. A preamplifier (V) with an integrated reference AC resistance and a lock-in amplifier (L) for measuring the signal level and the phase shift compared to the function generator, are further provided. Also a control computer (Sr) and a graph plotter (P) record an AC field frequency/time curve. ADVANTAGE - Gives real-time measurement with low cost. Short measuring time with full use of equipment to attain optimum measuring accuracy. Continuous progress of curve during total solidification. Can also be used for glass transition temp.