SCOPE
APPARATUS CONFINED TO OBTAIN THERMAL STABILITY OF HALOGENATED THERMOPLASTICS SUCH AS POLYVINYL CHLORIDE ETC. BY MEANS OF PH INDICATIVE PAPER, WHICH TURNS TO PINK COLOR WHEN MATERIAL LOST STABILITY.

PRINCIPLE
THE THERMAL STABILITY IS AN ACCELERATED METHOD TO DETERMINE THE RATE OF DEGRADATION OF PVC COMPOUND WITH TIME UNDER THE INFLUENCE OF TEMPERATURE. COMPOUNDS WITH HIGH THERMAL STABILITY CAN WITH STAND CONTINUOUS PROCESSING TEMPERATURES AND IT IS AN INDICATION OF PERFORMANCE OF THE CABLE AT NORMAL AND ELEVATED TEMPERATURES IN ACTUAL USAGE.
TERMINOLOGY
THERMAL STABILITY IS THE INDICATION TIME IN MINUTES FOR THE PVC COMPOUND AT 200 C, AFTER IT HAS BEEN KEPT IN THE TEST APPARATUS. THIS IS INDICATED BY THE PINK COLORATION ON PH PAPER PRODUCED BY THE EVOLUTION OF HYDRAULIC ACID GAS DUE TO DEGRADATION.
ABOUT THE APPARATUS

HEATING BLOCK:
CYLINDRICAL BLOCK WITH OUTER DIAMETER OF APPROX. 150 MM CONTAINS A TESTING BLOCK MADE OF ALUMINUM WITH OUTER DIAMETER 100 MM APPROX. BASE TYPE HEATING ELEMENT FITTED INSIDE. OUTER BODY MADE OF MILD STEEL WITH HEAT RESISTANT POWDER COATED PAINT. TEMP. RANGE WILL BE AMBIENT TO 200 C 0.5 C. NO. OF HOLES WILL BE BETWEEN 15 20 AND DIAMETER OF THE HOLE WILL BE 5 MM APPROX. DEPTH OF EACH HOLE WILL BE 60 MM APPROX.
CONTROLLING BLOCK:
CUBICAL BOX CONTAINS THE DIGITAL PID CONTROLLER WITH RTD SENSOR, ON/OFF TOGGLE SWITCH, LINE & LOAD INDICATOR. OVERALL BODY IS POWDER COATED WITH HEAT RESISTANT PAINT. WILL OPERATE ON 220 VOLTS AC 50 Hz.