Myron L ORP Calibration & Verification Solutions are specifically formulated for PT3 calibration, but excellent for accuracy verification of all other ORP instrumentation.  Myron L manufactures 80mV, 260mV and MLC Light's 470mV solutions in 2 oz. quantities and multi-packs.  Using Myron L ORP solutions as prescribed ensures any ORP measurement sensor is functioning properly to specifications. A temperature compensation table is supplied for instruments with uncompensated readings.