Bourdon-tube barometers usually consist of a sensor. Element that, as for an aneroid capsule, changes its. Shape under the influence. Of pressure changes pressure. Transducers and a transducer that transforms. The changes into a form directly usable by the. The display may be remote from the. Precise and stable digital instruments with. Quartz Bourdon tubes are used as working. Reference barometers in calibration laboratories. The item “VERY RARE ANTIQUE FRENCH BOURDON TUBE BAROGRAPH LEON MAXANT PARIS EARLY 20th” is in sale since Sunday, March 27, 2016. This item is in the category “Antiques\Science & Medicine (Pre-1930)\Scientific Instruments\Barometers”. The seller is “france*brocante” and is located in Paris. This item can be shipped worldwide.