PH reader - how often it should be calibrated?

[FishLover]

Just wonder how often it should be calibrated. I just found out mine was .7 off the other day. It was giving me the wrong information for about a month or two :x

[Ben]

In an ideal world Calibrating them once per week is the way to go. But every 2 weeks should be fine.

But it would also depend on which unit you are using.

I calibrate mine every 2 weeks.

Cheers
Ben

[Bad Inferno]

Do you make sure the foam in the cap does not dry out. Make sure its wet with distilled water. It keeps the reference electrode wet.

How often depends upon the meter....I would calibrate it often then stretch out the calibrations such that the error is acceptable to you.

What I mean is calibrate it every second day for a week and note down the error each time, if this is acceptable then calibrate it every 4-5 days and write the error down if this is acceptable keep stretching out the period between calibrations until you get to a point where you are comfortable that say every 2 weeks the max error would be +-.2.

All you really would need to do is standardise the meter at 7ph not a full calibration of 4 & 10.

rob

[FishLover]

Thanks guys.

I did the calibration about 3 months ago. I guess I should do more.

I need to buy some calibration solutions and some distilled water.