Project 8.3 - Evaluation of Self-Recording Thermal Indicators J. J. Mahoney OBJECTIVES The objectives of this project were to field test three new models of thermal radiation calorimeters - (only two types were suitable for use in this event), INSTRUMENTATION The types of instruments tested on ] (CHEROKEE) were: The Thermistor Calorimeter, in which the thermal radiation was measured by a "bead" thermistor embedded in a copper cylinder. The +f copper cylinder acted as the heat receiver, The Passive Indicator, In this instrument, chemical paints which changed colors at certain definite temperatures (all above 100°F) were put on the end of a block made of alternate sheets of different lengths, of aluminum and heat insulator, RESULTS DELETED ‘The results for the- Passive Indicators will be calculated for the preliminary report, (All except one of the Passive Indicators gave readable results). REMARKS Both type of instruments used were 180° angle receivers. This was Quite fortuitous in that the ground zero direction for the event was considerably off. The third type of thermal indicator, a thermocouple type with self COPIED/p - LANL Re OE .- 62 -