Process temperature
Machine 01 · AI_014
Last known value
185.0°C
No update since the last sample.
Data quality
Untrustworthy data must look untrustworthy.
A value is easier to evaluate when its condition, last update and reason are visible with it.
Stale
Stale
- Shape
- Dial with stopped hands
- Shown as
- Shown as “Last known value”, with its original sample time and its age.
01Failure modes
Three ways a number misleads.
Each one looks like an ordinary number until its condition is shown.
In range, but out of date.
A reading can look plausible and still be old. The value is kept, labelled “Last known value”, and shows its original sample time and its age.
Present, but wrong.
A reading that arrives can still be outside what is expected. It is shown with the Bad label and a specific reason.
Shown after the connection failed.
When a source connection is lost the last value can stay on screen. The loss is stated outright and the retained value is labelled.
02Anatomy of a reading
What a reading carries with it.
Healthy readings stay calm and readable. Exceptions become noticeable where they occur.
Stale
- 01Name and source tagWhich measurement this is, and where it came from.
- 02Value and unitThe number, with its unit kept beside it.
- 03Condition label and iconBoth, always. Colour never carries the meaning alone.
- 04ReasonThe specific reason, when a reading is flagged.
- 05Last sampleThe original sample time. It never changes to imply a fresh reading.
- 06FreshnessHow old the last sample is.
03Evaluation
Five questions to ask of any reading.
Tick the ones your current tooling can answer. Useful for any platform you evaluate, including this one.
0 of 5 answered