Bob Davis wrote: Relative humidity is the amount of water vapor in the air, versus the amount it can hold, at a given temperature. If the temperature is, say, 70 degrees, and the air is holding all the moisture it possibly can, the RH is 100 percent. Since warm air holds more water than cold air, if the temperature then rises, the RH would go down, since the warmer air would be capable of holding more water. Ambient humidity is just the relative humidity at a particular location, like in the living room where the piano sits. Exactly, Bob. Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. wrote: Suppose you have 1 liter of air and it is at 20 degrees Celsius. Suppose the measured humidity inside the container is 30%. Absolute humidity or relative humidity? If one increases the temperature without allowing any air to escape the humidity will remain at 30%. The absolute humidity would remain constant, but the relative humidity would decrease in the scenario above. If on the other hand one allows air to escape--then there are fewer molecules of air--and fewer molecules of water so the "relative" humidity will be lower. Impossible to predict without additional information. Are we still increasing the temperature? Are we allowing the environment in the one liter vessel to equilibrate with the surrounding atmosphere? Theoretically, if one opens the vessel, and if the humidity outside was 100%, then both absolute humidity and relative humidity could rise in the vessel. By itself, relative humidity has nothing to do with "letting air escape". Terry Farrell -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060327/b863d419/attachment.html
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