ph probe calibration

[jwalters103]

in the manual it say the first step is to set the calibration tolerance between 1 and 3. what exactly does this mean? or i guess i should ask, how do i know what to set the tolerance to?

 

[jwalters103]

also, when calibrating, the second measurement is supposed to be made at 7.00, but the provided buffer solution is 6.86. how do i account for the difference?

 

[AQD_ottawa]

as probes age their calibration reaction time changes, this does not mean they as yet require replacement just are taking longer to react.

So when a probe is new the tolerence is 1 (or 2 sometimes with the AQD probe) as the probe ages you may have to increase the tolerence to 3 to obtain non time out calibration

 

[jwalters103]

any ideas about compensating for the difference in ph of the provided buffer solution and the target ph of 7.0 during calibration?

 

[AQD_ottawa]

 

[jwalters103]

when calibrating, it asks you to place the probe in ph 7.0 solution, however the provided buffer solution for calibration is ph 6.86. that means that if i use that solution for calibration, then every time the profilux tells me that my ph is 7.00, it will actually be 6.86. this is a large enough of a difference to cause some complications

 

[AQD_ottawa]

This is temp compensated so dont worry. 6.86 temp compensted is 7.0

 

[BryanS]

Are there complete calibration instructions anywhere?

 

[AQD_ottawa]

Yes page 17 of the manual

 

[BryanS]

I did read that section, but it doesn't answer all my questions; 1) Do I unwrap the sensor? 2) Do I empty the contents? 3) Do I replace the screw on cover if I do empty the contents?

I assume I unscrew the cover and empty the contents, then leave the cover off to do the calibration and/or get PH readings from my tank.

Is that correct?

 

[AQD_ottawa]

1) yes otherwise you would be ready the storage bottle and not the tank

2) keep it for future storing if you ever keep the probe out of the water

3) If you like

 

[BryanS]

Thanks again, I just want to make sure I don't ruin great new equipment. This is the first controller I have ever used. It really can do so much more than I expected.