"Is the MTBF OK then Ragu ? "

Of course - 900 hrs - is good enough.

The pot will be a consumable that needs to be changed once a year - this particular section of the test rig will be used for about 2 hrs per day ( maximum )and thus it should last a year and half going by a very conservative estimate. Afterall in this particular rig I have pressure line filters that cost around 70USD changed once every two months.

Calibration of the new pot is an issue but that is also well under control - once recommended they follow it to the last word.

Raghu