An interesting aluminium German airship altimeter no. 20731 by G. Lufft Metallbarometerfabrik GmbH c1930

Airship altimeter having anodised 115mm dial with luminised indices, altitude calibrated in kilometres divided down to 100 metres, the upper part marked “Höhe In Km” (height in kilometres), the lower part with Lufft logogram and serial “No 20731.” Blued steel pointer with luminised tip, rotating bezel with reflector ring and luminised index, bevelled glass, the periphery marked “Flugpaltz Anzerger Verstellbar” (airfield adjustable).

The Vidie pattern rotating movement driven from a single 75mm diameter capsule tensioned on a C spring, column mounted pin quadrant and lantern pinion drive mechanism enabling precise zero setting to airfield height (QFE), external setting wheel. The movement maintained in back of the case on three blued spring steel leaves and centred to the dial via a circular track affixed to movement verso with corresponding press formed cup in case.

The whole contained within a spun and pressed drum form aluminium case, original calibration certificate to side together with three fixing keepers. Calibration port to verso.

Condition: The subject of a full service, conservation, and calibration under laboratory conditions, see performance chart from dynamic test. The movement working well across the altitude range.

The dial about fine, the indices clear and sharp, the glass with minor scratches and marks, enhanced by the camera. The aluminium case generally marked with minor abrasions.

Comments: The catalogue image is taken from the Lufft Barometers and Altimeters Catalogue of 1930.

As yet we have not been able to determine the type of airship this altimeter might have been fitted to. It is certainly intended for airship issue, the major clue in the calibration expressed in kilometres, a convention unique to airships. In addition, the instrument with a full scale deflection of 8,000 metres equivalent to 26,000ft is far in excess of the earlier fixed wing aircraft that might have carried an altimeter of this size and style. Post-war fixed wing aircraft of this period maintained much smaller panel mounted altimeters.