So, eager to work with pH, I bought an ExTech pH meter based on recommendation from people on this board. This morning using 4 & 7 calibration solutions, I set out to calibrate. Unfortunately, the ExTech read the 7pH solution as 5.97 and calibrated to that. So, I removed the batteries , pressed On/Off button for ten seconds, replaced batteries and tried again. I got the same result. Out of curiosity, I tried the pH4 solution. The ExTech measured that at 2.97. It seems this meter is off by 1.03. Though I would not trust this. Is there anything I am missing? Else I guess I will have to send it back.