SP Series is a thermal dispersion flow switch is a precise flow sensing device for liquids. The principle of operation is based on heat transfer. The SP thermal dispersion flow switch is offered with a variety of output types and materials of construction. No moving parts make the SP series a long lasting and high value flow switch. Feature: 1.No moving parts, solidstate performance and reliability 2. per second (150cm/s) measuring range for water; 1~118300cm/s) range in oil 3.304SS, 316SS, PVDF and polypropylene wetted parts 4.Maximum operating pressure up to 1,450psi (100bar) 5.Choice of NPN/PNP, N.O. or N.C. relay, or SPDT relay output 6.Standard and custom extended insertion lengths 7.Standard or high temperature, explosionproof units available 8.LED indication of flow status 9.Marine certified unit available