Res-Kem now offers calibration of Mettler-Toledo’s Thornton products including pH, ORP, and resistivity/conductivity probes. These probes are used with Thornton M200, Thornton M300 and 770MAX monitors.  770MAX and M300 Thornton Meters Installed in a Customer’s Water Treatment Plant  Our calibration service coverage area is the mid-Atlantic and New England States.  For Additional Information: Contact us …