conductivity question- strange thing?

[MAKDENTAL]

I'm sorry if this is covered elsewhere but I couldnt find reference to it:

I have just recalibrated my conductivity probe after cleaning in proprietary cleaning solution. I calibrated using GHL 50mS at 25 c and using "temperature probe1" (rather than Manual temperature) as the ref temperature in the tank turned down to 25 C as a temperary measure just to make it easier.

The strange thing is, at the end of calibration, the calibration program asks to save the new settings which I obviously do and at this point I havn't taken the probe out of the 50mS reference solution expecting it to keep reading 50 mS because its still at 25c, then over the next 20-30 seconds it climbs to 50.2mS. Surely it should still read 50mS? can some one please explain?

I repeated the proceedure to see what happened and got the same deviation. The ADC1 reading is 18 & ADC2 is 414.

Can someone please explain what's going on and should I now put in a density offset compensation? If so what value?

I normally keep my tank at 26 c keeping a mixture of SPS & LPS. I am now wondering once I get a true reading what Conductivity value I should aim for. previously I held it at 53.0 Msv