STS PTM/N/SDI-12 Low-Power Digital Level Sensor
SDI-12 low-power field data interface; 500 mbar–25 bar measurable range, accuracy to ±0.10% FS; nominal −5 to +80°C operating/process temperatures, stainless steel/titanium options.
Original STS documentation
PTM/N/SDI 12 official model page.
Certification/selection: No hazardous-area classification is attributed to standard variants by analogy with /Ex devices. Verify specific ordering code, process/electrical connection and model-specific safety certificate before use.
PTM/N/SDI-12 — low-power field logging
Protocol selection: SDI-12 is designed for digital environmental sensor networks and field data loggers; it is not RS485 Modbus RTU and not a standard 4–20 mA loop. Match the logger’s SDI-12 line interface, addressing, measurement command sequence and power-management states to this specific STS variant.
Hydrostatic measurement: Pressure-based water-level conversion requires liquid density, barometric-reference strategy, sensor elevation and submerged cable length. Verify the advertised 500 mbar–25 bar family range against the selected order code, not merely the broad family listing.
Deployment: Moisture ingress through cable terminations, vent tube blockage and lightning/surge exposure are relevant in unattended water monitoring. The related PTM.MT/N/Ex photo does not substantiate an Ex rating for PTM/N/SDI-12.