DPT & Relative Humidity Charts Handy Dandy Earth Science Reference Tables Page 747.

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DPT & Relative DPT & Relative Humidity Humidity Charts Charts Handy Dandy Earth Handy Dandy Earth Science Reference Science Reference Tables Page 747 Tables Page 747
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Transcript of DPT & Relative Humidity Charts Handy Dandy Earth Science Reference Tables Page 747.

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Slide 2 DPT & Relative Humidity Charts Handy Dandy Earth Science Reference Tables Page 747 Slide 3 : The ratio of the airs actual water content to its potential water vapor content at a given temperature. Relative Humidity Basically, relative humidity tells you how saturated the air is with water. Relative Humidity = Weight of Potential Water Vapor in Air at Saturation Weight of Water Vapor in Air Slide 4 A psychrometer is used to measure relative humidity. The dry bulb measures the air temperature The wet bulb gives a measure of how unsaturated the air isthe evaporation of water from the wet bulb lowers the temperature reading (and the evaporation depends on the saturation of the air) Slide 5 Dewpoint Temperature: The temperature the air would have to be cooled to saturate the air (causes water to condense Slide 6 The Dry Bulb Dont let it fool you. It is just a thermometer. Dont let it fool you. It is just a thermometer. It measures the air temperature. It measures the air temperature. Duh! Duh! 20C Slide 7 The Wet Bulb Has a little wet booty tied to the bottom. Has a little wet booty tied to the bottom. Gets cool when water evaporates. Gets cool when water evaporates. 12C Wet Booty Slide 8 A Dry Day A lot of moisture will evaporate. A lot of moisture will evaporate. The wet bulb will be a lot cooler than the dry bulb. The wet bulb will be a lot cooler than the dry bulb. 8C 20C Difference between wet bulb & dry bulb is 12 C. 20C14C 12C Slide 9 A Humid Day A little bit of moisture will evaporate. A little bit of moisture will evaporate. The wet bulb will not be much cooler than the dry bulb. The wet bulb will not be much cooler than the dry bulb. 14C 20C Difference between wet bulb & dry bulb is 6 C. Slide 10 Page 747 & 750 of your Handy Dandy Earth Science Reference Tables Warning #1: Be sure to READ the correct chart: DPT or RH Warning #1: Be sure to READ the correct chart: DPT or RH Warning #2: Dew Point Temperature IS NOT Difference between wet bulb and dry bulb. Warning #2: Dew Point Temperature IS NOT Difference between wet bulb and dry bulb. Warning #3: The wet bulb temp IS NOT the DPT. Warning #3: The wet bulb temp IS NOT the DPT. Slide 11 Dry-bulb temperature is your air temperature. 20 C Slide 12 14 C Slide 13 4 C Slide 14 Subtract (the difference) between the dry bulb and wet bulb Slide 15 14C 20C 20-14=6 Slide 16 16C 18C 18-16=2 Slide 17 8C 20C 20-8=12 Put it all together Relative Humidity = 11% Slide 18 10C 14C 14-10=4 Relative Humidity = 60% Slide 19 10C 14C 14-10=4 Dew Point = 6C The Dew Point Chart works the same way Slide 20 Try These. Dry Bulb Wet Bulb R Humidity DPT 26C 20 C 6 C 5 C 12 C 8 C 18 C 17 C 14 C 0 C -3 C 58% C 17 C 86% C 4 C 57% C 4 C 91% C 16 C 100% C 14 C 45% C -9 C Slide 21 More Difficult. Dry Bulb Wet Bulb R Humidity DPT 21C19C 11C 6 C 17 C 17C 2C -3 C 9C 6.5 C 70F 60 F 82% C 18 C 45.5% C -.5 C 100% C 17 C 20% C -17 C 69% C 3.5 C 52% C (50 F) 11 C (50 F) C 21 C C 15 C Slide 22 Slide 23