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Field results

Spec sheets describe what a sensor can measure. This page shows what one actually recorded: a real GrowProbe deployment, unedited apart from removing the site's exact location.

The deployment​

  • Device: Growprobe unit D0005
  • Site: a UK coastal aquaculture site, 15 m deployment depth
  • Duration: 1 April to 2 June 2026, 62.2 days continuous
  • Sampling: every 30 minutes, no gaps
  • Readings logged: 2,985 timestamped records across all five parameters, close to 15,000 individual measurements from a single charge and a single recovery visit

Temperature: 7.3 to 24.6 °C​

Average temperature tracked the season: 8.4 °C in April, 9.2 °C in May, then a step up to an average of 18.4 °C in the early-June readings as the water warmed. Full range across the deployment was 7.3 to 24.6 °C, typical for UK coastal spring into early summer.

Turbidity: 0 to 77.9 NTU​

68% of readings came back below 0.5 NTU, clear water most of the time, with occasional sharp turbidity events up to 77.9 NTU. About 3% of readings exceeded the sensor's calibrated 0-40 NTU range, so the highest events are captured but read with reduced precision above the calibration ceiling, see the turbidity / NTU glossary entry for what that range means in practice. One reading in the full 2,985 hit the raw sensor channel's hardware ceiling during the single highest-turbidity event, a real limit worth knowing about, not a defect: it happened once in 62 days.

Current: continuous tilt movement, not a static reading​

The tilt sensor's pitch and roll swung across nearly their full range over the deployment (pitch 0 to 178°, roll -179° to 179°), and more than half of all 2,985 readings (57%) showed the probe rolled more than 90° from vertical. That is a real, continuously moving current field, not a fouled or stuck sensor sitting flat. This particular dataset doesn't carry an independently validated tilt-to-speed conversion for its exact mounting, so it's shown here as evidence the current sensor is doing its job, not as a knots figure, see what is a tilt current meter and the specification for how tilt angle maps to an approximate speed.

What this costs per parameter​

One GrowProbe, five parameters, one deployment, one CSV: £1,495 ex VAT works out to roughly £299 per parameter. A single dedicated turbidity logger alone commonly costs more than that whole unit, see the full price comparison.

A note on this data​

This is one real deployment from one PEBL customer, anonymised here (site identity and exact coordinates withheld). It illustrates what the instrument actually records in the field. It isn't a statistical guarantee of performance at every site, conditions vary with location, depth and mounting.

Need help?​

Get in touch at hello@pebl-cic.co.uk.