UNE-EN 50131-2-4:2008/IS1:2014 Soil quality - Determination of pore water pressure - Tensiometer method (ISO 11276:1995) (Endorsed by AENOR in May of 2014.)
2021UNE-EN 50131-2-4:2021 Alarm systems - Intrusion and hold-up systems - Part 2-4: Requirements for combined passive infrared and microwave detectors
2014UNE-EN 50131-2-4:2008/IS1:2014 Soil quality - Determination of pore water pressure - Tensiometer method (ISO 11276:1995) (Endorsed by AENOR in May of 2014.)
2008UNE-EN 50131-2-4:2008 Alarm systems- Intrusion and hold-up systems- Part 2-4: Requirements for combined passive infrared and microwave detectors