Overview
Prism points a ±10° beam of 60 GHz coherent radar at a seat and reports, in real time, whether someone is sitting in it. There is no camera and no image, only an occupied or vacant state, so passenger privacy is built in. With the installation jig it is fitted with adhesive in under 30 seconds per seat, needs no change to the seat, and comes in single- and double-seat configurations with several mounting geometries for standard and first class.
It is certified for rolling stock: EN 50155 (electronic equipment on rolling stock), EN 50121-3-2 (electromagnetic compatibility) and EN 61373 (shock and vibration). EN 45545-2 (fire) does not apply, as each device is below the mass the standard tests; the material is rated UL94-V0. It runs on one or two 2,500 mAh LiMnO₂ batteries for about ten years, works from –20 to +60 °C, and has a temperature sensor built in. Prism is the sensor inside SeatSense, the seat-occupancy service LNER has fitted across its Azuma fleet, and it is supplied only as part of that service.
Specifications
- Radar
- 60 GHz coherent radar, ±10° beam
- Range
- 0.2–6.8 m, centimetre accuracy
- Sensors
- Radar, temperature
- Variants
- Single or dual sensor · 13 mounting variants
- Standards
- EN 50155 (rolling-stock electronics), EN 50121-3-2 (EMC), EN 61373 (shock and vibration); UL94-V0 material (EN 45545-2 not required below its mass limit)
- Protocol
- LoRaWAN 1.0.4, Class A
- Frequency
- EU868
- Configuration
- Both boards over LoRaWAN; on site with Android apps, Hugin (NFC) and SweIoT Toolbox (Bluetooth)
- Updates
- LoRaWAN board: firmware and VSM app with Hugin (NFC), VSM apps also over LoRaWAN. Radar board: firmware only over Bluetooth, with SweIoT Toolbox
- Battery
- 1 or 2 × LiMnO₂ 2,500 mAh, about 10 years
- IP rating
- IP54
- Operating temp
- –20 to +60 °C
- Dimensions
- 82 × 82 × 27 mm
- Mounting
- Adhesive
- Patent
- Pending (PCT/EP2025/079948)
- Availability
- As part of SeatSense
Key features
- ✓Railway certified: Certified to EN 50155, EN 50121-3-2 and EN 61373 (electronics, EMC and shock/vibration for rolling stock), in UL94-V0 material, and in service across a fleet.
- ✓No cameras: Radar returns occupied or vacant. No image, no identity, nothing to protect.
- ✓Single or dual sensor: One or two internal radar sensors and thirteen mounting variants: standard and first class, single and double seats, left and right.
- ✓Fitted in under 30 seconds: A jig positions the sensor under the luggage rack and the adhesive does the rest. No structural change, no cables, and about ten years on the batteries.