PIIIex Redox probe detection ?

[Maverick38]

Hello,

I have just tried to calibrate my Redox probe (PIIIex and probe are new).
and it gives the following results :
whether the probe is unplugged the value ADC read is 531mV
and when I plug the probe (unplugging all the other probes/control cables) the value is almost the same (oscillating between 530 and 534mV).

Of course with such a calibration, the value for redox potential read on the PIII is always -999mV.

Is this something you have already seen ?

Do you think I could plug the PH probe in the Redox socket to identify is the PIII is faulty or (if the value changes from the eternal -999mV) if the probe is faulty ?


Many thanks

Mav'

[Maverick38]

New update

I have the impression that in order to satisfactorily calibrate the probe there need to be an established connection between the PIII and the sump :
by this I mean that the potential of the sump seems to be needed via another probe (say for instance the conductivity probe) before you can calibrate the redox...

In a nutshell if you unplug all and just plug in the redox , it won t work no calibration is possible.
But if you unplug all and plug in first the conductivity calibrate it then plug in redox and calibrate the redox : it works...

Is this normal ? Is this too late for me and dreams become reality ? I will confirm tomorrow !

Mav'

[Matthias]

where and if other probes are plugged in doesn't matter when you calibrate a certain probe

if you see strange (or not changing) readings:- probe defective? probe plugged into wrong port?

[Maverick38]

Hello,

In terms of port I have checked I plug the right probe in the right socket.

Do you think I could plug the PH probe into the Redox socket to make sure the port works on the PIII side ?

I am using tunze pumps, is it possible that the tunze pumps are interfering with the redox probe as I have seen on the forum this has happened in the past it seems..

Mav'

[Matthias]

you could connect the pH-probe into the redox port, the ADC should change

if not: maybe defective port

was this a P3 upgrade?

[Maverick38]

After many attempts I managed to find someone who has read the Profilux 2 manual (I had only read the PIII manual so far) which is way more detailed than the PIII manual and explains in details the calibration process.

I thought what was called "null plug" was meaning "no plug" whilst it meant actually the strange plug with a metal back.

Have done so and now calibration is fine.

Still, the probe in the sump is jumping between 60mv and 120mV... but I guess it will stabilise gradually ...?

All the best to the profilux team !

The thingy is great !!

Mav'

[Matthias]

it should not jump so much, about 10 ... 20mV is ok, but jumping 60mV seems too much

maybe you first increase the signal filter

maybe you can identify some devices which cause this instability (by unplugging and checking what happens with the redox)

what happens if the probe is in a glas of water?