Whirling psychrometer for measuring humidity
1950-1953
Psychrometer scale, of paper on wooden frame.
Psychrometer by Casella
Clockwork aspirated psychrometer
M.O. Balloon psychrometer
1945
Whirler for psychrometer, c. 1918.
1918
Assmann psychrometer by C. F. Casella
1919
Wet bulb in aircraft psychrometer housing, 1940s.
1940-1950
Assmann psychrometer
1922
Aspirated electric psychrometer
1997
Strut psychrometer Mk VA wet and dry bulb alcohol in glass Fahrenheit thermometers
Casing for clockwork psychrometer
1940-1950
Assmann psychrometer by Friedrichs & Co
1950-1960
Clockwork psychrometer
1935-1945
August psychromete
1876
Aspirated psychrometer by Casella
1930
Clockwork aspirated psychrometer, Mk3
1971
Assmann psychrometer by Casella
1944
Clockwork aspirated psychrometer by Casella
1950-1970
Air Psychrometer Mark V, with aircraft wing strut mounting straps
Strut psychrometer
1930
Strut psychrometer Mark VB
1943
Direct reading psychrometer
1924
Comins electro-psychrometer by the American Moistening Co.
1910
Clockwork psychrometer by R. Fuess
1938
Clockwork and fan for psychrometer by Salmoiraghi
1940-1950
Whirling psychrometer
1950-1960
Whirling psychrometer
1920-1940
Aircraft strut psychrometer
1927
Regnault type hygrometer with mercury thermometer
1866
Wet and dry bulb hygrometer, British, 1986
1986
Aeroplane psychrometer Mark II, 1918-1922.
1918-1922