Field note · February 27, 2026

What is deliberately wrong with sensor-telemetry

Eight thousand readings from twelve machines across three sites, at ten-minute intervals, with drift, seasonal temperature, injected anomalies, and gaps where a gateway dropped offline..

1 min read ·Data quality ·quality practice

What is deliberately wrong with sensor-telemetry.

8,000 rows, 8 columns, one row per sensor reading. Eight thousand readings from twelve machines across three sites, at ten-minute intervals, with drift, seasonal temperature, injected anomalies, and gaps where a gateway dropped offline.

There are two failure modes deliberately hidden in here: a slow bearing-wear drift on vibration_mm_s for two machines, and sharp single-reading spikes that are sensor glitches rather than real events. A good anomaly detector separates them. Timestamps are not evenly spaced — the gateway at site RIV drops out for stretches, so resampling before modelling is not optional.

Something to try: Detect the drifting machines with a rolling z-score; tune the window. The SQL playground has it loaded already, and the data explorer will profile every column in one pass if you would rather look before you query.

sql
select *
from sensor_telemetry
limit 20;

The file is generated from a fixed seed, so the CSV you download today is byte-identical to the one from last year. That matters more than it sounds: it means a lesson can say "row 412 is the interesting one" and still be right in eighteen months.

Download it, break it, keep it. CC0 — no attribution required, no account, no email.