In calibrating a thermometer by setting only the freezing and boiling points, what assumptions are you making regarding the internal diameter of the thermometer and the expansion of alcohol?
When calibrating a thermometer by setting only the freezing and boiling points, we make certain assumptions about the internal diameter of the thermometer and the expansion of alcohol. These assumptions are necessary to ensure accurate temperature measurements.
First, let's consider the assumption about the internal diameter of the thermometer. In this method of calibration, it is assumed that the internal diameter of the thermometer is consistent throughout its length. It is essential for the accuracy of the calibration because any variations in the diameter could affect the way the alcohol expands or contracts as the temperature changes. Therefore, the assumption is that the diameter remains constant, allowing us to establish a consistent scale.
Secondly, we make assumptions about the expansion of alcohol. Most thermometers use alcohol as the working fluid. It is assumed that the expansion of alcohol is regular and predictable within the desired temperature range. Specifically, we assume that the expansion of alcohol is linear and evenly distributed across the temperature range. This assumption means that equal increments in temperature will correspond to equal increments in the expansion of alcohol.
To accurately calibrate a thermometer using only the freezing and boiling points, it is important to have confidence in these assumptions. However, it is worth noting that to achieve a more precise calibration, further calibration points or corrections may be required to account for any deviations in the assumptions made.