Redox probe calibration

[Ken250]

Is it possible to change the calibration solution variable? The current options are 220mV to 250mV. I have some AM Pinpoint ORP calibration fluid, but it is 400mV, outside of the ProfiLux range. Is it possible to adjust the calibration range so that I can use the Pinpoint fluid? Is there an advantage to using a lower mV calibration fluid over a higher mV fluid.

I got the Redox probe up and running last night. After calibration, the controller measured 3mV with the null attachment and 216mV in the GHL 220mV calibration solution. These variances seemed reasonable to me.

However, when I tested the probe in the 400mV Pinpoint solution, the probe read 360mV, which seems like a fairly large variance. Is there an explanation for this amount of variance? Is it reasonable?

 

[AQD_ottawa]

Hi

In a nut shell yes, Redox is not a precise variable but an assessment of value, i.e if you tank says 360mv and it suddenly drops over night by 100 points start looking for nemo he has probably pegged it and become a food source increasing your bio load, you can mimic this by leaving your grubby hand in the tank

Redox is not a defined science and more of a progressive snap shot of your systems loading.

Leave the Redox probe in the 400mv for 5 minutes then leave in tap water for 24 hours, recal with the GHL solution and then leave in the system for a week then recalibrate, it takes time for the probe to adjust itself and get enough ions around the platinum to establish a more precise reading.

In salt water Redox reacts a whole lot slower also than in fresh due to the density of the water

 

[Ken250]

Thanks Michael. Is it possible to adjust the calibration range so that I can use the 400mV solution to calibrate?

 

[AQD_ottawa]

That I am not aware of.

Be cautious with the 400Mv it is VERY corrosive, my carpet in the living room of my house back in the UK can vouch for that! So can a few jeans and T shirts

I have also ruined two probes by leaving it in the solution for too long it stripped out the membranes.

 

[Matthias Gross]

250mV is max