An air-bearing microinterferometer transducer is being developed to provide for increased accuracy, range, and linearity over conventional linear variable differential transformer (LVDT) transducers. The conventional LVDT's are used on multiple-probe sweep gauges to measure deviation from true surfaces to revolution. These LVDT transducers are null devices, and their high accuracy deteriorates rapidly as they move from zero setting. It is desirable to have a transducer with extended range to measure parts that deviate from conventional paths. The length-measuring interferometer is a well-established inspection device. However, constructing a microinterferometer that will fit inside a conventional 1/2-inch-OD transducer housing is a formidable task. Departure from the conventional interferometer construction is required. It will be necessary to transmit the laser beam into the microinterferometer with a self-focusing fiber optic cable. Miniature glassware has been obtained and a microinterferometer constructed inside an 0.315-inch-ID transducer. Fringes have been obtained by directing a laser beam into the transducer housing.