| Abstract: | Abstract— Very rapid heating is an important chondrule-formation process, and it has not been clear whether conventional equipment, such as a muffle tube furnace, is adequate for the simulation of heating on a timescale of seconds. We present a method for measuring the internal temperature reached by a charge during rapid heating when the thermocouple response lags. We have constrained charge temperatures by monitoring the time required to melt metal wires of various compositions and melting points placed inside charges with furnace temperature at 1400, 1500, and 1600 °C. The times required for melting of the metal wires define the temperature paths inside the charges. At 1400 °C, a charge takes 31 s to reach 1399 °C; at 1500 °C, a charge takes 10 s to reach 1495 °C; and at 1600 °C, a charge takes 6 s to reach 1538 °C. Heating rates in vertical muffle tube furnaces are adequate for studying flash melting processes (i.e., of «1 min duration) invoked, for example, in the formation of chondrules. |
