Good catch SCdawg. Turn of the fan close the vents and breath a different direction.

So for clarification, Filing is never what I intended to say. The red ADT diamond hone is of decent quality it is flat and is a very fine grain of abrasive. removes material at a very slow rate.

If you take a loupe and look at the knife edges of your scale you will see imperfections. One big problem with beam scales is that people leave them assembled with the beam sitting on the base where the fulcrum is getting dull over time. They get banged around and such and this compounds the problem ending up with a scale that is inconsistent and that, is inaccurate.

If you have a scale that works as intended I recommend the practice of removing the beam carefully when not in use. A properly tuned and cared for beam scale can be unbelievable consistent and accurate.