Tracer Study Sample Logger

A digital clipboard for chronological water sampling. Tap once at the moment of the grab; enter the bench reading whenever the meter catches up. Runs entirely offline; the log persists in this browser via localStorage.

Clock discipline: the whole point of a tracer log is matching timestamps against the SCADA historian later. Before the first sample, compare this device's clock to the plant historian's clock and note any offset — a two-minute skew looks like a baffling-factor error at analysis time.

No samples logged.

Notes

Why one-tap timestamps

Handwritten sample times are the weak link in a field tracer study: the tech is holding a bottle, a reagent kit, and a phone, and “about 10:35” gets reconstructed later. Capturing the device timestamp to the second at the grab, and back-filling the residual after titration, keeps the time column trustworthy — which is the column the T10 analysis actually depends on.

Matching against SCADA flow data

Export the CSV and join it against the historian's flow trend on the timestamp column. If the device clock offset was noted at the start, apply it as a constant shift. Sampling on a fixed cadence (e.g. every 2 minutes through the breakthrough curve, stretching out on the tail) makes the join and the curve both cleaner.

References

  1. EPA Disinfection Profiling and Benchmarking Guidance Manual — tracer study procedure and T10 determination. https://www.epa.gov/dwreginfo/surface-water-treatment-rules
  2. State primacy agency tracer study protocol, where one governs the facility.