SK80-BFT | SK80-BFTLFT | Watermark®
The KNX soil moisture sensor reliably measures soil moisture and soil temperature – and, depending on the model, also air humidity and air temperature.
The maintenance-free Watermark® technology realistically simulates root behavior and provides precise information about the soil’s actual water demand.
Integrated control functions enable demand-oriented, automatic irrigation directly within the KNX system.

Installation guide
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SK80-BFT-WMT
The measuring system SK08-BFT-WMT records the soil moisture and the soil temperature, which is measured with the Watermark® sensor. The measured values can be output and used for control tasks.
Applications:
The sensor is suitable for irrigation in field and specialty crops such as vegetables, berries, asparagus, vineyards and orchards, potatoes, sugar beets, hops, and seed production. It can also be used for garden and lawn areas, golf courses, sports fields, and landscaping applications. Not suitable for potted plants.

ETS-Application
Technical Data
| SK80-BFT-WMT | |
|---|---|
| Supply voltage | KNX 21 .. 32V DC |
| KNX load | 10mA |
| Operating/storage temperature bus coupler | -25 .. +60°C / -25 .. +80°C |
| Environmental humidity | 0 .. 100% non-condensing |
| Dimensions | see drawing |
| ETS-application | Arc_S8.knxprod / S8-BFT |
| Protection class bus coupler | IP54/65 |
| Soil moisture Watermark® | |
| Measuring range | 0 .. ~220000 Pa |
| Resolution | ± 0,01 Pa |
| Soil temperature PT1000 | |
| Measuring range | -25 .. +50°C |
| Resolution / accuracy | ± 0,01°C / Klasse DIN B |
SK80-BFTLFT-AFF-WMT
The SK80-BFTLFT-AFF-WMT measuring system records soil moisture, which is measured using the Watermark® sensor, as well as soil temperature. The measuring system also has sensors for air humidity and air temperature, so it can provide a more comprehensive picture of the current situation in the garden or greenhouse.
Applications:
The sensor is suitable for irrigation in field and specialty crops such as vegetables, berries, asparagus, vineyards and orchards, potatoes, sugar beets, hops, and seed production. It can also be used for garden and lawn areas, golf courses, sports fields, and landscaping applications. Not suitable for potted plants.

ETS-Application
Technical Data
| SK80-BFTLFT-AFF-WMT | |
|---|---|
| Supply voltage | KNX 21 .. 32V DC |
| KNX load | 10mA |
| Operating/storage temperature bus coupler | -25 .. +60°C / -25 .. +80°C |
| Environmental humidity | 0 .. 100% non-condensing |
| Dimensions | see drawing |
| ETS-application | Arc_S8.knxprod / S8-BFTLFT |
| Protection class bus coupler | IP54/65 |
| Soil moisture Watermark® | |
| Measuring range | 0 .. ~220000 Pa |
| Resolution | ± 0,01 Pa |
| Soil temperature PT1000 | |
| Measuring range | -25 .. +50°C |
| Resolution / accuracy | ± 0,01°C / Klasse DIN B |
| Air humidity | |
| Measuring range | 0 .. 100% r.H |
| Resolution / accuracy | 0,02% / ±3% r.H (20..80%) at +20°C, else ±5% |
| Air temperature | |
| Measuring range | -25 .. +80°C |
| Resolution / accuracy | 0,02°C / ±0,4°C (5..60°C), else ±0,8°C |
