HI 991300 Portable pH/EC/TDS/Temperature Meter Low Range EC & TDS HI 991300 has been designed to offer you  pH, conductivity, total dissolved solids and temperature measurements all in a slim, lightweight, portable unit. From purified to brine water measurement, you can select the meter which will work best with your range of conductivity for greater precision. There are only 2 buttons, yet you ... Read More »