I'm not sure if anyone else had problems.
unit #1: gave me false reading on the out side. The output side kept giving me a "err" reading which ment the TDS was greater than 999ppm, it was connected after the DI cartridge. sent that back got unit #2.
Unit #2: work for 2mo, then drop dead, I've changed the battery to check to see if it was working....dead. I did not leave the unit "on", it's only turned on when i want to check the TDS.
I'm not sure if anyone else had problems with there units, the manuf. made good on the warrenty I maybe got lemons. I've been using a Hanna hand held unit for several year, it's work fine for me. Just got to calibrate it once a year.
John- not to ruine your GB. Just thought buyers should be aware.
Peter