What do the certificates tell me about the devices?
Sigfox Verified certificate is given to modules that encode Sigfox messages correctly and their emitting characteristics are in line with the Sigfox guidelines. The Sigfox Verified certificate is not given to final assembled devices, but only to the Sigfox module presented by the manufacturer.
With Sigfox Verified certificates, there is no further classification.
Sigfox Ready certificate is given to the final Sigfox-enabled products that include battery and casings. There are several classes of the Sigfox Ready certificate and they are given to the device based upon the transmission strength. Read more about our Sigfox Radio Class: https://ask.simplehw.eu/sigfox-radio-class
However, since the measurements are done in an artifical environment (in a lab) and the requirements are artificial as well, the certificates provide just a rough indication of how well the devices perform from a radiotechnology perspective.
In general, Sigfox is really on the edge of what is technologically possible and it is rather tricky to achieve good radio performance.
If you'd like to read a detailed description, visit https://build.sigfox.com/.