CSC Scientific Instruments DuNuoy Tensiometer. A precision instrument used for laboratory measurement of surface tension. Produces precise readings of upward interfacial and surface tensions by the ring method to values reproducible to within ±0.05 dyne/cm. Unit is mounted on a cast tripod support with leveling screws. Utilizes quick–ring method for readings within 15-30 seconds. Measurements made on circular scale graduated in dynes/cm. Specified for determining interfacial tension of ASTM Std. D971, C1331, and D1590.