A simple way to measure ORP accurately. Designed for use with the gel-filled ORP/ATC Triode™ electrodes, Cat. No. 9179BNMD and 9179BN; refillable ORP/ATC Triode electrodes, Cat. No. 9180BNMD and 9180BN; glass-bodied ORP electrodes, Cat. No. 9778BNWP and 9778SC; and Sure-Flow® ORP electrodes, Cat. No. 9678BNWP and 967800.