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Tekbox TBSST04 SDI 12 Soil Temperature Probe

The TekBox TBSST04 is a rugged, multi-level soil temperature sensor with an SDI-12 interface. It is designed for reliable, long-term deployment in soil or compost monitoring applications, offering measurements at up to three distinct depths in a single probe.

Key Features

  • Supports 1, 2, or 3 PT1000 sensors in one probe, selectable per model (TBSST04_1, TBSST04_2, TBSST04_3)
  • Each segment (between sensors) can be up to 3 meters long; total probe length can reach 9 meters
  • Interface: SDI-12 standard v1.4
  • Supply voltage: 6 to 16 V
  • Idle current: ≈ 23 µA
  • Accuracy: ±0.1 °C, with three-digit resolution
  • Operating temperature range: –40 °C to +80 °C
  • Built from UV-resistant resin / fiberglass composite tube, potted with silicone for protection
  • Diameter: ~ 18 mm; wall thickness ~ 3.5 mm
  • Cable: Standard 3 m; custom lengths available

Measurements & Operation

  • Can report temperature for each depth level individually or all at once
  • Extended SDI-12 commands allow:
  • Setting unit (°C or °F)
  • Custom polynomial calibration per depth level
  • Offset corrections
  • Comes factory-calibrated and ready to use
  • Supports both SDI-12 v1.3 and v1.4 command sets

Use Cases

  • Soil temperature profiling in agriculture and research
  • Compost monitoring (temperature critical to avoid overheating)
  • Integration with SDI-12 data loggers or remote telemetry systems
  • Environments requiring deep profiling with minimal disturbance