Checker by Hannah ph meter

[earlystart35]

Anyone use these? I just got it and apparently the guy calibrated it. Does the numbers ever stabalize for any period of time? I have test strips and the difference is quite big so want to make sure before I ph the water and ruin something...Thanks

 

[lushgreen]

Hannah are a reputable brand, they make all kinds of laboratory equipment.
A decent pH probe should give a stable reading within 60 seconds. It's possible that the reference probe inside the glass bulb has an air bubble trapped on it. Give the meter a good shake and re-test.
You really should get some pH 4.0 and 7.0 calibration fluid (it's cheap) and calibrate every 3 weeks or so.

If you don't have the instructions, here's a link:
https://shop.hannainst.com/downloads/dl/file/id/1735/manhi_98103.pdf