Lee,
What you are seeing with that statement from Western is a combination of marketing misinformation. First of all, they say:
Unlike analog gauges, the Caliber III never requires calibration, there are no springs to stretch or moving parts to wear out.
This is a reference to the mechanical analog hygrometers. What they are saying is true for every digital hygrometer out there. That doesn't mean they don't need to be calibrated, just that they don't have the same calibration issues as an analog.
The second part is that they say not to perform the salt test. That is the important part. Just because performing the salt test is ONE way to calibrate a hygrometer does not mean it is the same as using a Boveda kit to do so. Totally different things. Western is simply protecting their warranty so that people can't attempt to send the hygrometer back when they spill salt water all over the hygrometer while trying to perform the salt test.
You ABSOLUTELY should use a Boveda pack to calibrate EVERY SINGLE digital hygrometer. There is no danger, there is no damage that the Boveda can cause to the Caliber III. Western claims +/- 1%. Personally, I don't buy that. Nowadays you can actually test that yourself.
