Measurement

A measurement is used to represent time-series data that can originate from a device or a complex system.

A measurement is made up of

• Timestamp
• Tags
• Metrics

Timestamp

When sending a measurement to Senfi, timestamp is represented as tm_source, milliseconds since epoch.

Take note that timestamp refers to when the reading or measurement is taken, not when it is sent. There can be cases where readings are taken, and later sent in a batch. In this case, the timestamp of the measurement will be older than the time of sending.

Metrics

These can be raw values from the sensing device (eg. rain_level), or derived values (eg. is_flooding). You can decide to compute the derived values by yourself and send it, or to make use of computed measurement to do it.