Answer :
Final answer:
Calibrating a constant volume gas thermometer at two fixed points establishes a temperature scale by creating a linear scale between the points, based on the proportional relationship between gas pressure and temperature changes. Therefore, the correct answer is option B.
Explanation:
The purpose of calibrating a constant volume gas thermometer at two fixed points is to establish a temperature scale. By using two known temperature reference points, such as the temperature of dry ice and boiling ethyl alcohol, it allows for the creation of a linear scale between the points, which can be used to interpolate other temperatures. This method relies on measuring the gas pressure, which varies proportionally to the temperature changes at constant volume, and is exemplified by the relation P - TTP = PTP where TTP represents the triple point.
Overall, this calibration process helps to ensure accurate and consistent measurement of temperatures, which is fundamental in various scientific and industrial applications. Metrologists have designated the constant-volume gas thermometer as a standard for calibration since it provides reliable results when extrapolated to situations like zero pressure correlating with absolute zero temperature.
