Psychrometr Augusta

Psychrometr Augusta

Psychrometr Augusta – psychrometr stosowany do pomiaru wilgotności w pomieszczeniach, w których ruch powietrza wywołany jest tylko konwekcją naturalną (przeciwnie do psychrometru Assmanna)[1]. Korzystając z tego psychrometru wilgotność względną powietrza odczytuje się z tabeli lub z wykresu psychrometrycznego i oblicza ze wzoru psychrometrycznego:

gdzie:

– temperatura wskazywana przez termometr suchy,
– temperatura wskazywana przez termometr mokry,
– ciśnienie nasycenia pary wodnej w temperaturze
– ciśnienie nasycenia pary wodnej w temperaturze
– ciśnienie powietrza w którym przeprowadzany jest pomiar,
– stała psychrometryczna.

Stałą psychrometryczną określa wzór:

Dla pomiarów w pomieszczeniach przyjmuje się prędkość powietrza równą W = 0,5 m/s, wówczas A = 0,000785 1/°C.

Udoskonaleniem psychrometru Augusta jest psychrometr Assmanna w którym wymuszono ruch powietrza wokół termometrów.

Historia

Przyrząd do pomiaru wilgotności powietrza składający się z suchego i mokrego termometru został skonstruowany w 1828 roku przez niemieckiego fizyka Ernsta Ferdinanda Augustusa (Ernst Ferdinand Augustus)[2].

Przypisy

  1. ↑ Pomiary wilgotności powietrza. Politechnika Lubelska, 2013. [dostęp 2018-12-27].
  2. ↑ Psychrometer. [dostęp 2018-12-27].

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Journal of the Royal Horticultural Society of London (1873) (14764108305).jpg
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Identifier: journalofroyalho4187roya (find matches)
Title: Journal of the Royal Horticultural Society of London
Year: 1866 (1860s)
Authors: Royal Horticultural Society (Great Britain) Royal Horticultural Society (Great Britain). Extracts from the proceedings
Subjects: Gardening Botany Horticulture Fruit-culture
Publisher: (S.l. : s.n.)
Contributing Library: Harvard Botany Libraries
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Text Appearing Before Image:
ter,both these elements are known, and the one now exhibited (fi g. b)is fixed on a metal frame, so that it cannot be injured by water inthe greenhouse. I consider that instruments of this class, for thispurpose, should be good and inexpensive. The pair of thermometers,as shown, are very nearly without errors at every part of theirscales, and could be used for outdoor determinations of temperatureand humidity of the air if necessary. Mr. Ackland (Home andThornewaite, 123, Newgate Street) has agreed to furnish theseinstruments thus mounted at 15s. the pair, upon the agreement thathe will send them to me for examination before mounting, and sellthose only to horticulturists which are furnished with my certifi-cate of their accuracy, and that I am permitted to reject all instru-ments which may have an error as large as three-tenths of a MR. J. G. BAKER ON DRAC2ENA AND CORDYLTNE. 27 degree at any part of their scales. These instruments have beenapproved by the Eoyal Horticultural Society.
Text Appearing After Image:
A BA, Ground Thermometer—the stem of the instrument should he provided-with a circular plate to rest on the soil as stated in the text; b, Wet andDry Bulb Thermometer. VII. On Dracaena and Cordyline. By J. G. Baker, F.L.S., Assistant Curator of the Kew Herbarium. (Eead June 26, 1872.) There are two genera of arborescent Liliacese which since thebeginning of the century have been distinguished by botanists byuniversal consent, and which are well-marked from one anotherboth by structural differences and by habit, which seem lately, sofar as nomenclature goes, to have drifted into a state of fusion inour collections and trade catalogues in a way that certainly would 28 ROYAL HORTICULTURAL. SOCIETY. be protested against if Lilies were either Ferns or Orchids. Thetwo genera to which I refer are Draccena and Cordyline, somemembers of which everyone knows, and everyone who has a con-servatory cultivates. The Dragon Tree of the Canaries is a plantabout which everyone has read, and the greatjournalofroyalho4187roya

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