Waterproof Multi-Parameter, Single Probe Water Testers - HI 991300 & HI 991301These instruments measure pH, conductivity, TDS and temperature in one easy to use meter, utilising a single probe.**HI 991300** - measures low range conductivity and TDS **HI 991301** - measures higher ranges Both instruments provide full scale pH readings Automatic calibration and temperature compensation Selectable EC/TDS conversion factor Adjustable conductivity temperature coefficient Dual level LCD Battery level and stability indicator Simple calibration procedure Probe is housed in a rugged plastic sheath with reinforced 1m rubber cable and stainless steel DIN connector **HI 991300** |    ---|--- EC/TDS calibration | Automatic 1 point at 1382ppm (conv.= 0.5), 150ppm (conv.= 0.7), 1413 μS/cm (others) **HI 991301** |   EC/TDS calibration | Automatic 1 point at 6.44ppt (conv.= 0.5), 9.02ppt (conv.= 0.7), 12880 μS/cm (others) **Both HI 991300 and HI 991301 ** |   EC/TDS ratios | Se