Calculating Relative Humidity Practice Use table from MJ 2006 Paper 1 Q4

Wet & Dry Bulb Thermometer Wet/Dry Bulb thermometer Hygrometer DRY WET

Relative Humidity Table

Reminder You need 3 things to calculate the %RH using the table on the previous slide 1.Dry Bulb Temperature 2.Wet Bulb Temperature 3.Depression of the wet bulb (Dry – Wet = Depression of wet bulb)

Example 1.Read off thermometers 2.Dry = 28ºC Wet = 25ºC 3.Depression of wet bulb = Dry – Wet = 3ºC 4.Read off table Answer = 76% RH

Practice DryWetDep%RH A3228 B262 C375 D2273 E264 F281 G2621 H24

Answers (Mark out of 16) DryWetDep%RH A B C D E F G H