Gradus is the ideal solution for the allocation of thermal consumption costs in indirect metering situations. These electronic heat cost allocators are installed directly on the radiators and must be calibrated according to the type of radiator.
• Two temperature sensors
• Built-in wireless wM-Bus
• Can operate with fixed or variable scale (configuration via optical interface)
• Complies with EN 834
| Device type | 2-sensor device; measurement: 1 or 2-sensor mode |
|---|---|
| Approval | German decree on cost allocation (HKVO), cert. no. A1.01.2013; EN 834; UNI 10200 |
| Service life, estimated | 11 years + 1 |
| Scale Unit or product scale | Wide range of Kc factors available |
| Remote sensor | Retrofittable; cable length: 2 m or 5 m |
| Temperature range | 2 sensors: 35 °C–95 °C (up to 105 °C with remote sensor) 1 sensor: 55 °C–95 °C (up to 105 °C with remote sensor) |
| Ambient temperature | -25 °C ÷ +60 °C |
| Minimum temperature difference ΔT | 4.5 K |
| Interfaces | Optical (M-Bus protocol) – USB opto head required Wireless M-Bus (optional) |
| Display | LCD, 7 digits + special characters |
| Values displayed | Current consumption, due date, due date value, check sum |
| Billing date options | Yearly, selectable (except 29.02) Monthly, selectable (days from 1 to 28) |
| Storage of monthly values | 132 monthly and 132 semi-monthly values |
| Measurement stop during summer months | May/June/July/August/September: selectable |
| Tamper detection | Break contact |
| Power supply | 3 V lithium battery |
| Protection rating | IP41 (mounted) |
| Device dimensions (h × w × d) | 95 mm × 38 mm × 30 mm |
| Remote sensor cover dimensions (h × w × d) | 26 mm × 12 mm × 10 mm |
| Telegrams | Short telegram, OMS compliant (AMR): current consumption, due date, due date value, error code Long telegram* for walk-by reading: current consumption, due date, due date value, 15 monthly values and 15 semi-monthly values, error code |
|---|---|
| Transmission power (max.) | 10 dBm |
| Frequency | 868 MHz |
| Modes (EN 13757-4) | S1, T1, C1 |
| Encryption | AES 128 / Maddalena Master Key |
| Date of radio activation | Yearly, selectable (except 29.02) |
| Data transmission interval | 2–240 min. (2 min.)* |
| Time/day | 0 a.m.–12 p.m. (8 a.m.–6 p.m.)* |
| Days/week | Monday–Sunday (Monday–Friday)* |
| Weeks/month | 1–4 (1–4)* |
| Months/year | January–December (January–December)* |
| Reading system | Hardware Arrow Collect and USB wireless M-Bus receiver |
| Software | Reading: Arrow Mobile (for Windows) Set-up: Device Monitor (for Windows) |
