Calibrating the Redox probe shows ADC = 000 with Null Plug and 220mv Cal Fluid

[KwaiSeng]

Hi,

Need some help here with the Redox PRobe calibration on the Profilux 3Ex.

I have tried to calibrate the Redox Probe, when I insert the null plug, it shows 000 after a while.

thereafter, the null plug was replace by the ORP probe dip in the 220 mv Calibration fluid. Again, it shows ADC = 000.

Throughout the calibration, the ADC reading did not fluctuates. It always stay at '000'.

Once the Calibration is complete, the ORP reading always show -999 mv.

Just wonder what went wrong with this. I have done the same with a new Redox probe, exactly the same observation as above.

Any help is appreciated. Thanks in advance.

Thanks!

rgds
KwaiSeng

[Gunther]

Are you shure you have used the Redox input and not the one for conductivity? The conductivity input looks the same and the marking "Redox " is between the two BNC sockets.

[KwaiSeng]

Hi Gunther,

Thanks for responding. Yes, I have validated that the probe is indeed connected to the Redox input port.