Humidity: This entry is a record of the measurement environment. In cases where an evaporation trap is not used, it is important to record the humidity because the evaporation volume rises as the surrounding humidity decreases. However, if an evaporation trap is used, the evaporation volume is minimized and measurement can be performed without worrying about the surrounding humidity. Since entering the humidity does not affect the conversion of mass to volume, the humidity value does not have to be entered.
Atmospheric pressure: The range of atmospheric pressure change in a single location is generally ±15 hPa. Therefore, even though an average (fixed value) is used, the pressure fluctuation can be locked in easily between ±30 hPa. The effect of pressure changes on volume conversion in this case is ±0.003%. Consequently, it is acceptable to enter a representative value for the atmospheric pressure of the location.