Hydrophonic
New Member
Anyone have problems with cheap TDS pens? Tried testing a couple in conductivity standard of 2.76mS, but the both are in PPM and display about 1000ppm. Is this correct? The manuals say they have a conversion factor of 500. Does this mean that they should display 1380ppm in 2.76mS standard? Am I missing something?
They're both cheap Chinese units from eBay and neither has a calibration screw to adjust it... Should I just get a refund?
They're both cheap Chinese units from eBay and neither has a calibration screw to adjust it... Should I just get a refund?