Good Water Warehouse, of Fullerton, Calif., introduces the OAKTON Instruments’ TDSTestr 30 and TDSTestr 40 microprocessor-based pocket sized conductivity and TDS (total dissolved solids) meters that are perfect for raw water and reverse osmosis product water analysis. These meters feature all push-button operation, hold (freezes readings), automatic temperature compensation, automatic shut-off to conserve batteries, self-diagnostic error messages, auto ranging, and push-button calibration.