Javascript must be enabled to view this site.

Read our system requirements.

Gordon Dobson s original ozone spectrograph
1 of 1

Gordon Dobson s original ozone spectrograph, result 1 of 1

Item Details
Open Artstor
Available to everyone
Gordon Dobson s original ozone spectrograph
Spectrograph designed by Gordon M. B
See all records within the set
Work Type
Oxford, Oxfordshire, England, United Kingdom
aluminium alloy
brass (copper, zinc alloy)
cotton (textile)
mahogany (wood)
wood (unidentified)
overall: 200 mm x 1310 mm x 300 mm, 10.795kg
Spectrograph designed by Gordon M. B. Dobson in 1924 and used by him at his home laboratory in Boars Hill, Oxfordshire for the measurement of atmospheric ozone. The instrument detected ultraviolet (UV) light reaching Earth s surface from the Sun. Because ozone in the stratosphere absorbs UV wavelengths, UV intensity indicates ozone concentrations.
The instrument used a chlorine and bromine vapour filter to absorb visible light. A Fery prism and optical wedge produced a spectrum on a photographic plate. The intensity of spectral lines at ozone-absorbing UV wavelengths was measured relative to a reference wavelength unaffected by ozone.
University lecturer Gordon Dobson was fascinated with atmospheric ozone, supposing that its absorption of certain wavelengths of light would affect the circulation of the atmosphere. Recognising the need for regular ozone measurements to test these ideas, he built this spectrograph in 1924, and shortly afterwards five others to the same pattern. He found ozone concentrations fluctuated far more than had previously been supposed, varying daily, seasonally and also geographically.
By the late 1920s he had adapted the instrument s design to use photoelectric cells rather than photographic plates.
During the mid-twentieth century Dobson s spectrophotometers were despatched worldwide for ozone measurement, particularly during the International Geophysical Year of 1957-8. In 1985, dramatically declining ozone concentrations were recorded by a Dobson instrument in Antarctica; subsequent research confirmed the existence of an ozone hole above the continent. This ultimately stimulated international action to ban ozone-destroying CFCs in industry.
Modern versions of Dobson s instruments are still used to monitor stratospheric ozone today, in conjunction with other instruments both on the ground and on satellites.
Accession Number
ID Number
Image and original data from Science Museum Group
The source metadata displayed in the Description field is released under a Creative Commons Attribution 4.0 license.
All other source metadata is released under Creative Commons Zero.
File Properties
File Name

Now viewing <!-- <button class="sort">013</button> -->Gordon Dobson s original ozone spectrograph