The IS41M provides high accuracy in checking large surfaces for planarity deviation, and also during equipment installation. It contains no components requiring high-precision manufacture. The instrument is convenient to use and can be prepared for operation in not more than 10–15 min. The data do not need complicated processing and provide direct information on the deviation from planarity at the relevant point.
Components of a machine can be set up in a single plane under direct control of the instrument, and the surface can be oriented at any angle in space.
The instrument is suitable for use in the laboratory and under plant conditions and even in the open air, provided there is no precipitation.
Translated from Izmeritel''naya Tekhnika, No. 8, pp. 48–49, August, 1978.