... 4.Message indicators Benchtop Digital Calcium Ion Concentration Meter Parameters: Calcium Ion Concentration Range10-1~5~×10-7 mol/L ... readings.6.USB Communication Interface.Features:1.Ion concentration mode directly displays readings in ppm, ppt ... Meter Included: Calcium Ion Selective Electrode (Made in US, Assembled in China),Temperature Probe, Power Adapters. Benchtop Calcium Ion Concentration Meter ...