Hanna HI 98129

Hey guys. March 3rd i ordered a Hanna HI 98129 Combo Meter. March 6 I recieved it. Ive read the instruction as to how to calibrate the pH properly.

First using the 7.01 buffer, after it switches it 4.01, when thats complete it jumps back to regular readings.

I turned the meter off, rinsed under tap water and tested the 7.01 soloution, but it reads 6.89-6.9.1.

Why is this?

Did you quickly rinse the meter between the 7.01 and 4.01 solutions? You could cross contaminate the 4.01 if you don't do a quick rinse. That could lead to a calibration problem..

yes rinsed after every use

There is a known issue with calibration with a batch of these meters. Mine wouldn't calibrate and as long as I had the receipt they replaced it after about 5 min on the phone troubleshooting. The replacement meter works perfect.

The only complaint i have is that PH readings are slow but EC and TDS are immediate

When you call tech support you'll get voice mail. They always called me back with 30 to 90 min