GHL PH Probe Calibration Issues

[rockworm]

For calibrating the GHL PH probe, should I change the tolerance to 3? I ran it at one on the PH4.0 and it told me I had a defective probe. I changed the calibration to 2 and it was successful in calibrating at 4.0. I then rinsed the probe in RODI, dried it off and set it in the 7.0 solution. Aghin it tells me defective probe. I have wasted an hour now. I have a second probe, but I do not want to start over and have the same problem.

If I have to set it at 3, then will it work? If so, how reliable is the measured PH value.

Needless to say I an getting frustrated.

 

[AQD_ottawa]

Simple answer, never ever put a pH probe in RO or distilled water you will damage the membrane. RO is way too harsh for the membrane to tolerate and can contaminate the KCL gel

Leave soaking in pH 4.0 for a couple of hours and then recalibrate you should be ok.

If still no go drop off to me next week, leave with me for 24 hours and I will see if I can bring it back for you.

 

[rockworm]

Doh. Did not know that about rodi. I will soak and then try again.

 

[rockworm]

I went ahead and ca;ibrated the second PH probe. It worked. Thanks for the instruction AQD_ottawa. I will let the first probe soak for a couple hours in the PH 4 solution. I did not need the second until I bring the CA reactor on line. However, I will try calibrating later and if it works, well I will have two for now.

 

[AQD_ottawa]

Ok no probs let me know how you get on.

 

[Tony Romano]

I am having a bit of trouble as well - mine does not finish and drops back into main menu before finishing on 9.0. 2 weeks ago i had to set tolerance to 3 to get it to calibrate. I don't think i ever put in RO, but could be wrong. Probe is around 5 months old.

 

[AQD_ottawa]

place in 4.0 over night.

Probes can last 5 month or they can last up to 2 years, generally the latter depending on regular cleaning and calibration.

pH probes fall under the catagory of degenerative (word for the day ) and as such it is impossible to determine a length of life.

 

[Tony Romano]

Thanks - what is proper way to clean?

 

[AQD_ottawa]

best in 4.0 solution or plain tap water.

 

[Harry_Fish]

I have a cheepie probe I want to store.

I do not have any storage solution.

Can I use Vinegar, or one of the PH cal solutions?

 

[AQD_ottawa]

use pH 4.0

 

[Tony Romano]

For salt water calibration use 7.0 and 9.0? Just making sure I am correct in my understanding of manual.

(sometimes I miss real basic stuff)

 

[Harry_Fish]

I only have 7 and 9

can I make 4.0 with vinegar and ro?

 

[AQD_ottawa]

not advised

You can get both stoage and pH 4 online at most places or at your local LFS it does not have to be GHL fluid

 

[AuS MaDDoG]

We have also had problems with the pH probe calibration here in Aus, no problems when calibrating with the 4.0 solution but tends to always time out and advise defective probe when using the 9.0 solution.
I agree with AQD_ottawa leave the probe sit for longer in the 9.0 solution before starting the calibration and it always tends to work after that.

Cheers
Tony.

 

[Tony Romano]

how long ia a little? real question is how long will PF allow?

 

[jcat90reefer]

can someone let me know where the calibration page is? i dont see it....

 

[jcat90reefer]

nm figured it out but its being funny maybe it didnt calibrate correctly