Bidspirit auction | Vintage Metzger Mechanical Strain Gauge

Vintage Metzger Mechanical Strain Gauge Pair - This remarkable lot features two vintage mechanical extensometers (strain gauges) manufactured by the renowned precision instrument makers F.F. Metzger & Son of Philadelphia, Pennsylvania. Highly prized by collectors of scientific and industrial history, these instruments were designed for precise structural testing, utilizing a mechanical lever and dial indicator system to measure minute deformations in materials. The top set features an 8” strain gauge paired with an F.F. Metzger dial indicator, while the bottom set features a 2” strain gauge paired with a B.C. Ames Co. dial indicator. Both instruments are housed in their original velvet-lined, leatherette-covered cases. A historical paper label inside one case reads ”Chemical Storage Fellowship, Mellon Institute, 4400 Fifth Avenue, Pittsburgh, Pennsylvania,” and vintage handwritten notes indicate a lever ratio of 10 for both units. Both instruments show minor surface wear, light oxidation, and minor scuffs to the metal consistent with age and field use; the cases exhibit exterior scuffing and minor material loss, but the hinges and latches remain functional. Case 1: H 1.75”, W 10.5”, D 7.5”. Case 2: H 2.25”, W 9”, D 6.5”. See photos for condition. From the Dale Beeks collection.