... Reduction Potential and ion concentration.electrode. FEATURESDirect readout of ion concentration unitsTwo-point push-button calibration with ... compensation for best accuracy under fluctuating temperaturesViewing of electrode slopeAutomatic operation message promptsExpanded memory stores ... points Temperature Compensation0~100oC, 32~212oF, Automatic or Manual Built-in Ion modeNa, Ag, K, NH3, CL, F, ...