BRITISH CROWN COPYRIGHT, THE MET OFFICE / SCIENCE PHOTO LIBRARY BRITISH CROWN COPYRIGHT, THE MET OFFICE / SCIENCE PHOTO LIBRARY
Electrical resistance thermometers, arranged to obtain wet and dry readings. The exposed metal rods (upper left) measure the dry temperature. The covered rod (lower right, covered in a wet fabric) measures the wet temperature. Comparing the two gives a measure of humidity. Electrical resistance in metals varies with temperature, allowing temperature readings to be derived from such measurements. The screen that protects the equipment from wind and rain has been removed. This equipment is being operated by the Met Office, the UK's national weather monitoring and forecasting service.
Model release not required. Property release not required.