9526392 Getting This grant provides $136,670 in support of the costs of developing a technique to measure the absolute temperature of geological materials at high-pressures in a recently developed gas-piston cylinder apparatus at the University of Colorado. Specifically, the technique, entitled Johnson noise thermometry measures the electrical noise generated in a resistor (thermocouple) at elevated temperature. Due to the chemically inert and hydrostatic environment generated in the argon gas- piston cylinder, delicate and complex instumentation can be used in the cylinder to make corrections for the effect of pressure on thermocouple emf thus enabling measurement of temperature that is independent of the pressure. This development will significantly expand the range of pressure (up to 6 GPa) for which calibrated thermocouple temperature measurements can be made. ***
