ABH-200
Online fridge monitor
The vaccine-fridge unit
USB-powered Wi-Fi monitor with e-paper and a PT100 probe channel — the WHO-PQS-style unit for vaccine fridges and cold rooms.
Design visualization · 88.2 × 69.9 × 16.8 mm · probe pod 30.5 mm
ABH-200 — every number a QA team asks for
Channel-level accuracy, memory depth in readings, enclosure geometry and the firmware trust chain — the full picture before you ask for the pilot.
| Product type | Online · Wi-Fi monitor |
| Sensing channels | 3 (Probe temperature · Ambient T + RH) |
| Probe temperature | PRB-PT100-3W Class A · −50…+200 °C · ±0.15 °C at 0 °C |
| Ambient T + RH | SHT41 in a sealed, vented chamber · ±0.2 °C typ |
| Measurement accuracy | Probe element ±0.15 °C at 0 °C (PT100 Class A, IEC 60751) · channel ±0.62 °C uncalibrated → ±0.36 °C after 4-point factory calibration |
| Display & indication | 1.54″ e-paper 200 × 200 · −25…+50 °C · holds last reading while asleep |
| Connectivity | Wi-Fi 2.4 GHz (ESP32-C3-MINI-1U) · MQTT over TLS 1.2+ — Internal FPC · ≤2.33 dBi (Espressif-certified type) |
| Power | USB 5 V (≈29 mA) · CR2032 keeps the clock ≈10 yr through outages |
| Battery life | Always on when powered · RTC cell ≈10 yr — No logging during a mains failure — RTC survives it |
| Memory | 16 MB W25Q128JV · 409,600 readings · separate never-erased audit region |
| Sample interval | 1 s minimum · configurable |
| Enclosure | 88.2 × 69.9 × 16.8 mm · probe pod 30.5 mm · Healthcare-grade disinfectant-resistant PC/ABS · UL94 V-0 · white |
| Ingress protection | IP54 in use (cable fitted) / IP65 capped (design targets) |
| Mounting | Keyhole (2×) + bonded 10×2 mm magnets |
| Operating band | −25 to +50 °C (e-paper limit) |
| Firmware | Signed .abhfw packages · dual-bank A/B · RSA-2048 · trial boot with automatic rollback · MQTT over TLS 1.2+ with per-device credentials · X.509 client certificates / mTLS on the roadmap |
| Factory identity | ABH-[model]-[YYWW]-[5-digit sequence] — factory identity written to the ID EEPROM |
| Ports | USB-C power · M12 probe port (probe pod) |
The ABH line is at the design-frozen, pre-production stage: every enclosure has passed generated fit-check geometry (791/791 checks, 20/20 SKUs) and every battery-life, drop, thermal and IP figure shown is a calculated or simulated design estimate — measured values replace them as validation hardware runs. Regulatory marks above are the certification roadmap, not held certificates.
- E-paper readable by gloved operators in low light; holds the last reading when asleep
- Thermal gap pad and opt-in USB power save cut SHT41 self-heating from +2–4 °C to +0.1–0.9 °C; calibrated compensation closes the rest
- Wall- or magnet-mount at the fridge; probe through the M12 pod
- Excursion/fault LED visible on walk-by
- Vaccine & pharma fridges (2–8 °C)Always-on USB monitor with e-paper, alarm LED and PT100 probe — the WHO-PQS-style vaccine-fridge use case.
- PRB-PT100-3W — PT100 immersion probePRB-PT100-3W-3M · PRB-PT100-3W-5M · PRB-PT100-3W-10M
- ABH-200-E — External-probe fridge monitor
- ABH-200 datasheetPDFFull specification, applications and probe options
- ABH range overviewAll 20 SKUs and the platform story
- Platform capability briefSoftware, compliance and architecture
Datasheets describe the current design release (ABH-PLATFORM 0.0.4). Battery-life and IP figures inside are calculated design estimates; measured values follow validation hardware.
One PCB, one firmware, one compliant record
One 80 × 50 mm 4-layer platform PCB — 146 parts, single-sided SMT — becomes 20 SKUs by BOM selection and a SKU record in the on-board ID EEPROM.
Signed .abhfw packages · dual-bank A/B · RSA-2048 · trial boot with automatic rollback
MQTT over TLS 1.2+ with per-device credentials · X.509 client certificates / mTLS on the roadmap
Plug an offline logger into a PC and it enumerates a FAT16 drive with README.TXT, DATA.CSV and an ECDSA P-256-signed REPORT.PDF — a self-verifying trip record.
Probe channel templates live in the ID EEPROM; the platform tracks NIST-traceable calibration certificates, due dates and reminders per probe.
Certification roadmap: EN 12830:2018 — temperature recorders · CE — RED / EMC / safety · FCC Part 15 · WHO PQS E006 — vaccine cold chain · IEC 61010-1 / IEC 62368-1 · UN 38.3 / IEC 62133-2 — cells & packs — targets, not held certificates.
Put the ABH-200 to work
Book a demo and we'll scope a pilot around your sites — quantities, probes, alert rules and the reports your QA team will hand the inspector.