The Clock Drift reading is the difference, measured in seconds, between the time reported by your Crystal Water Monitor's internal clock and the time recorded by Crystal Water Monitor's servers when the check-in is received. It is reported every 20 minutes alongside each check-in.
Crystal Water Monitor has an internal clock that keeps time between connections. Like all clocks, it can gradually drift away from the true time, running slightly fast or slow. Clock Drift tracks how far off the internal clock is.
Why does this matter?
Accurate timestamps are important for making sure your readings are recorded correctly and that your water chemistry history is reliable. A small amount of drift is normal and nothing to be concerned about. When drift grows large enough, it can cause readings to appear at the wrong time in the app or make it harder to correlate your chemistry data with events like chemical additions or pool usage. Large clock drifts can also cause security problems when using TLS to securely send your water information.
What causes clock drift?
- Temperature changes can cause the internal clock to run slightly faster or slower over time
- Extended periods without a network connection, during which the clock cannot be corrected
- Normal variation in the monitor's hardware components
What happens if drift gets too large?
The monitor's clock is corrected automatically during check-ins with Crystal's servers. In most cases, drift is kept well within an acceptable range without any action needed on your part. If it becomes too large your checkins may be discarded to prevent issues.