Cold-Chain Monitoring: A Field Guide for UK Logistics Operators

## Why cold-chain monitoring is harder than it looks The compliance bar is not the hard part. The hard part is keeping the data clean, trustworthy and audit-ready while the kit lives in a freezer truck for four years. This guide covers the **three deployment mistakes** we see operators make most often, and how cold-chain monitoring works when it's done right. ## Sensor selection — accuracy isn't everything Most operators over-specify accuracy and under-specify reliability. A ±0.1°C-rated probe that drifts after a year of vibration will cost you more in re-calibration than a ±0.3°C probe that holds spec for three years. We recommend: - **Probe placement** matters more than probe accuracy for GDP compliance - **Cable rating** must match the load — silicone for sub-zero, PVC for ambient - **Sintered stainless tips** survive cleaning cycles that destroy plastic caps Calibration certificates from accredited labs are non-negotiable for MHRA audits. ## Data retention — the one thing auditors always check A pharmacy temperature monitoring solution should retain raw readings for at least **two years** under UK GDP rules. The mistake we see: operators retain the *summary* but not the *raw* data, then can't answer follow-up audit questions. IoT-WorkS gateways write raw telemetry to local storage and back-fill cloud on reconnect — which means a 6-month network outage doesn't break your audit trail. ## Common deployment failures 1. **Single probe per reefer** — fails GDP for cargo over a certain volume 2. **No calibration schedule** — annual cal is the bare minimum 3. **No alarm tree** — alerts that go to a generic inbox die in the inbox [Talk to engineering](/contact/) for a free deployment review.