Barograph, illustration. A barograph is an instrument that measures and records atmospheric pressure as part of weather forecasting. It consists of a flexible metal box called an aneroid cell or capsule (centre right), which contains a vacuum. Small changes in atmospheric pressure (blue arrow) cause the capsule to expand or contract. These movements are amplified by mechanical levers attached to a pointer. The pointer is a writing device which traces the variations in position onto graph paper on a rotating drum. High pressure generally indicates a period of dry weather, whilst low pressure weather systems tend to be rainy. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library |
Bildgröße: | 4331 px × 4331 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |