I've noticed that a ds3232 rtc chip had a time difference of 0.06 ppm after 16 months (2.5s / 16 months). This seems ridiculous low (datasheet: 2ppm), so I would like to check this with several chips simultaneously.
I have not yet any good idea's on how to accomplish this. The I2C address is the same. Is there a simple method to multiplex I2C?