Manufacturing Sensor Data: Check Quality Before Building Dashboards

Check units, timestamps, missing values and sensor context before using production data for quality decisions or maintenance dashboards.

China Thermic Editorial Team

A dashboard can display precise-looking numbers while hiding unreliable inputs. Before using sensor data to explain product quality or equipment condition, verify what each value represents, when it was measured and whether the measurement was valid.

CREATE A TAG DICTIONARY

For each signal, record the equipment location, physical quantity, unit, expected range, sampling interval and owner. Distinguish a controller setpoint from a measured value. A field named temperature is insufficient if it could mean furnace air, product surface or cooling water.

CHECK TIME ALIGNMENT

Confirm that systems use a consistent time basis and that clock changes are handled. Product movement through a continuous line introduces a delay between a process measurement and a downstream test. A useful comparison follows the same product or batch rather than simply matching two readings with the same clock time.

HANDLE MISSING AND INVALID VALUES

Define how the system identifies a disconnected sensor, a communication interruption and an out-of-range result. Do not silently replace missing values with zero. Retain quality flags so a graph does not turn invalid data into an apparent process excursion or an apparently stable trend.

TEST ONE REAL USE CASE

Choose a recent production event and reconstruct it from the stored data. Check whether the records explain the product identity, recipe, process condition and test result. Compare the reconstruction with operator records. Correct discrepancies before expanding the dashboard to more equipment.

FREQUENT QUESTION: DOES A HIGHER SAMPLING RATE ALWAYS HELP?

No. Sampling should match the event being investigated and the behavior of the sensor. Collecting more poorly identified measurements increases storage without necessarily improving decisions.

TECHNICAL REFERENCE

NIST's digital-thread work addresses information reuse and traceability across the product lifecycle. The checks above focus on preparing dependable inputs for that connection. https://www.nist.gov/ctl/smart-connected-systems-division/smart-connected-manufacturing-systems-group/enabling-digital