ORP calibration

[20vturbo]

I am trying to calibrate my ORP probe for my AC III and I got PH 7 and 4 but when I read the manual it says I need "Quinhydrone and pH 4.00" and "Quinhydrone and pH 7.00"

"Create a saturated solution of Quinhydrone and pH 4.00 calibration solution"


"Create a saturated solution of Quinhydrone and pH 7.00 calibration solution"

any ideas what they are talking about?

 

[melev]

I've never tried to do that, and don't know. Sorry. you might ask in the chemistry forum.

 

[20vturbo]

ok, Thanks!

 

[ecook]

According to Scott, you can use just regular 4 and 7 fluid to calibrate it...however my readings have been off on my ORP probe since my recalibration...stating that the ORP is at 220 :eek1: which I don't think to be accurate.

I may be wrong though, and maybe my orp really is that low...

 

[20vturbo]

hmmm thats what I thought, but I wasnt sure if i missed something, I know mine is wrong bc it says mine it 400 something...and it should be way lower IMO

 

[janakaybravo]

I've got the one from the AC3 and the one I had already with Milwaukee ORP controller. They are reading about the same and I have never calibrated either one. It's reading 393 on the AC3 and 417 on the Milwaukee.

When I added ozone, I researched about the ORP probe, and it's not an exact thing, nothing like the ph reading or temp reading.

That 400 plus number sounds high though if you're not adding ozone. Have you tried taking a soft toothbrush and cleaning the little end of the probe? I think I read somewhere that you can't really calibrate them like you can a ph probe.

I read Randy Holmes-Farley's articles on ozone in the reef aquarium, I believe on this site. Very interesting reading.

 

[20vturbo]

yeah, not adding o-zone and I have tried cleaning the probe.