01 · CAPTURE
Time-stamped at the sensor
Hardware time-stamp applied at the point of capture — UTC, to the millisecond. No reliance on the gateway clock.
Data integrity & trust Tamper-evident from day one
Every reading.
Every reading.
Hashed and GPS-locked.
A continuous, tamper-evident record across every site — designed to be admissible under the UK rules of evidence (PACE 1984, Civil Evidence Act 1995), with UK data residency and ICO registration.
The integrity model
Four layers of integrity.
Every sensor reading enters the chain through four sequential integrity steps. The platform fails closed: if any layer can't verify, the reading is quarantined and the chain root flags amber.
02 · HASH
SHA-256 hashed end-to-end
Payload — value, sensor ID, timestamp, location — hashed and chained to the previous reading from the same sensor. Any edit detectable.
03 · GPS-LOCK
GPS-locked to the site
Deployed coordinates baked into the hash. Move a sensor off-site and it reads "out of geofence". Sample-bottle custody locked the same way.
04 · SEAL
Weekly root sealed
Each week's hashes roll up into one published root — independently verifiable by inspectors, insurers and auditors. No relationship with BlueMetric required.
Live chain extract
What the chain actually looks like.
A real sample of how the evidence chain rolls forward. Every line is a sealed reading. The block-root at the foot is the verifiable hash anyone can check.
[2026-05-21 09:14:32.142Z] sensor=savoy/TMV-012 value=44.6°C loc=51.510,-0.121 hash=b81f3a2c…3cd2 prev=a7f9…b001
[2026-05-21 09:14:32.151Z] sensor=claridge/HOT-S03 value=61.8°C loc=53.481,-2.241 hash=7e028afd…f01a prev=2bc1…e8f4
[2026-05-21 09:14:32.163Z] sensor=ashbury/SENT-04 value=56.2°C loc=51.454,-2.587 hash=c4a1be77…9b76 prev=04e3…1c2a
[2026-05-21 09:14:32.174Z] sensor=haven-lodge/TMV-007 value=43.1°C loc=51.245,-0.500 hash=9f5c2244…2d80 prev=ee72…8910
[2026-05-21 09:14:31.998Z] sensor=novotel/COLD-B1 value=19.6°C loc=51.503,-0.018 hash=1b87902d…4ee5 prev=88dd…43a7
[2026-05-21 09:14:31.987Z] sensor=hilton-edin/LOOP-A value=62.1°C loc=55.953,-3.181 hash=d20309cb…81fa prev=39a0…0f12
[2026-05-21 09:14:30.000Z] BLOCK-ROOT · week=20 · count=2114 · root=4f2c8ab9...a8d1 · SEALED
[2026-05-21 09:14:32.151Z] sensor=claridge/HOT-S03 value=61.8°C loc=53.481,-2.241 hash=7e028afd…f01a prev=2bc1…e8f4
[2026-05-21 09:14:32.163Z] sensor=ashbury/SENT-04 value=56.2°C loc=51.454,-2.587 hash=c4a1be77…9b76 prev=04e3…1c2a
[2026-05-21 09:14:32.174Z] sensor=haven-lodge/TMV-007 value=43.1°C loc=51.245,-0.500 hash=9f5c2244…2d80 prev=ee72…8910
[2026-05-21 09:14:31.998Z] sensor=novotel/COLD-B1 value=19.6°C loc=51.503,-0.018 hash=1b87902d…4ee5 prev=88dd…43a7
[2026-05-21 09:14:31.987Z] sensor=hilton-edin/LOOP-A value=62.1°C loc=55.953,-3.181 hash=d20309cb…81fa prev=39a0…0f12
[2026-05-21 09:14:30.000Z] BLOCK-ROOT · week=20 · count=2114 · root=4f2c8ab9...a8d1 · SEALED
This is a real chain-extract format. Live operators verify with the platform's public token in seconds — independent of any BlueMetric staff.
Illustrative only · BlueMetric OS
Why it matters
Records that survive scrutiny.
Tamper-evident continuous records change three things, in order: what gets recorded, what gets challenged, and what gets paid out.
CRIMINAL
Designed to be admissible.
Built to meet the UK rules of evidence: PACE 1984 (Police and Criminal Evidence Act) and the Civil Evidence Act 1995. Tamper-evident chain of custody.
CIVIL
Defensible peer-comparison evidence.
Continuous, tamper-evident evidence narrows what "reasonable peer behaviour" looks like. As continuous monitoring spreads, the bar rises with it.
INSURANCE
Supports insurer conversations.
Underwriters see a continuous record, not a stack of paper inspections. We don't promise discounts — but evidence strong enough to support insurer conversations is what we deliver.
Accreditation status
What we hold, and what's in progress.
Only one item is held today — ICO registration. Everywhere else, we say so. Honest, current, no over-claim.
REGULATOR
ICO registration
Held. UK GDPR / DPA 2018 registration.
INDUSTRY
LCA
Legionella Control Association — accreditation in progress.
CONTRACTOR
SafeContractor
Application in progress. Health-and-safety policies on request under NDA.
LAB
ISO 11731
Sampling performed via accredited partner laboratories.
NHS framework alignment and healthcare-specific accreditations are in progress. We do not currently hold any further UK government cyber-security or digital-evidence scheme certifications; when we are awarded one, we will publish it the day it lands. ICO registration number to be confirmed on this page before public launch.
Rational economics
The cost of compliant-but-not-safe.
Two cases that turned on execution, one statutory clock, and one subscription that records execution end-to-end.
£3M
Bupa Care Homes · 2023
Legionnaires' fatality. Compliant on paper. The risk assessment didn't match the actual risk profile; contractor verification gaps were apparent.
£1.8M
G4S · 2021
Scalding fatality. Periodic checks in place. The execution failure was on the ground; nothing in the record showed otherwise until it mattered.
10 days
Awaab's Law statutory clock‡
Social housing, in force 27 October 2025. From awareness of a damp/mould hazard: investigate in 10 working days, begin remedial action in 5; emergency hazards in 24 hours — with alternative accommodation at the landlord's cost if not made safe.
<1%
BlueMetric subscription, annualised
Relative to the cases on the left. One subscription per site. No CapEx, no per-visit fees, no ad-hoc remediation invoices.
‡ Hazards in Social Housing (Prescribed Requirements) (England) Regs 2025; sits within s.10A Landlord & Tenant Act 1985. Awaab's Law does not, of itself, set a representative penalty figure; the operational cost shown here is the statutory clock and the alternative-accommodation duty in the emergency pathway.
See the chain on your own estate.
Pilot on one representative building. Low-cost. The hash root is verifiable from day seven.