I am using the Bruker Tensor II AquaSpec FTIR instrument to analyze my protein samples in aqueous solution, but when I run the necessary tests at startup I get failure at this specific test.

I give plenty of time for the detector to equilibrate to LN2 temperatures and for the water bath to bring the cell and water to 25 C. I've washed with plenty of water but still get the error.

The expected value is 1554.353 with a tolerance of 0.050. The values I get are 0.054 or 0.055 below. Five thousandths of a wavenumber doesn't seem like it will have any impact on my results, but I don't want to make measurements with an instrument that is flashing a big red warning sign.

Any suggestions are greatly appreciated.