GB180763A - Improvements in or relating to computing-appliances or indicatingscales for correcting altimeter readings - Google Patents

Abstract

180,763. Wimperis, H. E., Bygrave, L. C., and Capon, R. S. March 3, 1921. Multiple-indication apparatus ; index hands.- The observed readings of an aneroid altimeter are corrected for temperature at height by means of relatively slidable members bearing scales cf height and temperature. The apparatus is described as a calculator distinct from the aneroid instrument; but it may be incorporated with the latter in which case one member is set automatically by the mechanism. In the construction shown in Fig 1 for use with isothermally-calibrated altimeters a disc carries a height scale a having equal graduations from 6,000 feet upwards but increasing graduations below this height. Pivoted on this disc is a second disc b provided with Centigrade, Fahrenheit and absolute temperature scales which open out towards their lower ends. In use the disc b rotates so that an index d points to the uncorrected height reading whereupon the true height may be read opposite the observed temperature. In the form shown in Fig. 2 for use with altimeters corrected for mean temperature, the smaller disc f bears two height scales while the larger disc h is provided with an evenly divided scale of heights g and a temperature scale m. In Fig. 3, a single disc i has an observed height scale and a true height scale and supports a pivoted arm p graduated at l for temperature and having an index pointer k. In a further form the temperature member bears two scales namely of mean temperatures and of true temperatures at height, and also has duplicated index pointers.