Glossary

Regulatory

HACCP — Hazard Analysis and Critical Control Points. A risk-based methodology for food safety. Mandated for EU food businesses by EU 852/2004.

ŠVPS — Štátna veterinárna a potravinová správa Slovenskej republiky. The Slovak food and veterinary administration.

TrinkwV — Trinkwasserverordnung. The German drinking-water regulation, which implements EU 2020/2184 with specific Legionella thresholds.

DVGW W551 / W553 — German Association for Gas and Water technical worksheets. W551 covers Legionella prevention in domestic hot-water; W553 covers ringline sizing.

GxP — umbrella for Good {Manufacturing, Distribution, Laboratory, Clinical} Practice. Pharmaceutical and medical-device regulatory quality systems.

GDPR — General Data Protection Regulation, EU 2016/679. EU-wide personal-data law.

DPA — Data Processing Agreement. The contract between data controller (you) and data processor (us, when you ask us to send emails to your staff).

SCC — Standard Contractual Clauses. EU Commission-published template clauses for processor agreements.

Sensor terms

SHT3x — Sensirion family of digital temperature + humidity sensors. The chip inside the Shelly H&T and many DIY breakouts. Accuracy ±0.4 °C, ±2 % RH.

BME280 / BMP280 — Bosch sensors. BME280 has T + RH + pressure; BMP280 has T + pressure only. Cheap, popular in DIY.

SCD41 — Sensirion NDIR-based CO₂ sensor. The cheapest accurate CO₂ sensor we know of; ~€40 in single quantities.

NDIR — Non-Dispersive Infrared. The detection method real CO₂ sensors use. (Cheaper "eCO₂" sensors infer CO₂ from VOC; they are not appropriate for compliance.)

PT100 / PT1000 — Platinum resistance temperature detectors. ±0.5 °C class B at 25 °C; the standard sensor when you need calibratable accuracy.

Thermistor — A cheaper temperature sensor based on resistance change; common in HVAC. ±1.0 °C typical.

RH — Relative humidity, as a percentage. Always in the context of a specific temperature.

VPD — Vapour Pressure Deficit. Used in greenhouse / grow-room operations to characterise drying potential. Derived from T + RH.

LQI / RSSI / SNR — Radio link quality indicators. LQI is the Zigbee per-link quality 0–255; RSSI is the received signal power in dBm (more negative is worse); SNR is the signal-to-noise ratio in dB.

Protocols

LoRaWAN — Long-range, low-power radio for sensors. EU868 is the European band; US915 is the US band. Coordinated through a Network Server (TTN, ChirpStack).

TTN — The Things Network. A free, community-run LoRaWAN network server with EU presence.

MQTT — Lightweight publish/subscribe protocol. We use MQTT 5 only in production; MQTT 3.1.1 was the long-time default but lacks user properties and shared subscriptions.

MQTTS — MQTT over TLS, port 8883 by convention.

mTLS — Mutual TLS. Both client and server present certificates. Our MQTT bridge uses mTLS exclusively.

LWT — Last Will and Testament. An MQTT message the broker publishes when a client disconnects ungracefully.

OpenSense terms

Account — The top-level container. One human, one billing relationship.

Site — A physical location.

Device — A hardware unit.

Sensor — A logical input on a device.

Channel — A sensor + the rules attached.

Measurement — A (channel, ts, value) tuple.

Rule — A configuration that defines when a channel is OK / WARN / ALARM.

Event — One transition in the channel state machine.

Vertical — The use-case preset for a site: HACCP, Legionella, server-room, climate, energy.

Grace period — How long a channel may stay out-of-range before the alarm fires.

Silence window — A planned period during which alarms still record but do not notify.

Ingest token — A bearer token (ds_live_…) that authenticates one device.

Idempotency key — A client-supplied key that makes a mutating endpoint safe to retry.

Industry references

ASHRAE TC 9.9 — ASHRAE Technical Committee 9.9 publishes thermal guidelines for data centres. The de-facto reference for server-room environments.

Bizot Group — An international group of major museum directors; publishes the "Bizot Green Protocol" on environmental standards for loaned art.

REHVA — Federation of European HVAC associations. Publishes ventilation guidance for schools and offices.

eu-central — Hetzner's data-centre region in Falkenstein, Germany.

Things we are not

• We are not SCADA. We are a SaaS for small operations.
• We are not a Testo replacement for regulated pharma cold-chain.
• We are not a hardware vendor.
• We are not GxP-attested.