Frequently asked

SDI-12 is an industry-wide, vendor-neutral bus for environmental sensors. Multiple sensors share one cable; the logger queries them in turn. Benefits: low power draw, long cables (>500 m), free choice of sensor brand.

We use SDI-12 v1.3 with Bluetooth setup for in-field configuration, no need to plug a laptop into the logger.

No. The Aquatos Web LTX ships with a multi-IoT SIM that roams in 30+ countries, nothing to configure. On request we deliver the device without a SIM so you can fit your own M2M SIM, useful when your utility has fixed contracts with a specific provider.

IP68 means: fully dust-tight and watertight under continuous submersion. For Aquatos in concrete terms: tested to 1.5 m over multiple days, in real-world use for years in gauge shafts and Wadden Sea sites.

The submersible probes (Aquatos mini and nano) reach up to 100 m water column depending on the pressure cell. Operating temperature: −25 °C to +85 °C, both under permafrost ice and in Sahara heat.

TLS-encrypted transport from logger to web portal, BSI-compliant (German Federal Office for Information Security). Firmware updates are signed and encrypted (tampering with the device is detected and refused).

BLE configuration is protected by a 6- to 16-digit PIN with a time lock after failed attempts. Data is stored exclusively on EU servers (GDPR-compliant). Audit logs are available on request.

The Aquatos Web LTX delivers over 3 million measurements and 30,000 transmissions per battery, up to 10 years in the field, depending on measurement and transmission interval.

With active configuration (e.g. 5-minute measurement and hourly transmission) typically 5–7 years. The Aquatos mini and nano without cellular load typically run even longer.

Aquatos Web LTX: when you need real-time data, flood early warning, utility monitoring, research project with cloud uplink. LTE-M plus NB-IoT fallback, 24 SDI-12 channels, fully programmable.

Aquatos mini: when you visit the site regularly and can collect data via Bluetooth, typical for groundwater wells without mobile coverage. 1- or 2-inch housing, 250,000-record memory.

Aquatos nano: when the shaft is small and you want sensor, logger and BLE radio in a single 1-inch tube, wells, narrow gauge shafts. No cable to a separate logger needed.

Standard buoy (red-and-black coated): spherical float with central mast and anchoring rod, robust against current and waves, for rivers, lakes, reservoirs and coastal areas.

Shallow-water buoy (black): compact hemisphere on a stainless-steel support frame, operational from 20 cm measurement depth, low wind-attack surface, for shallow and sheltered waters such as ponds, wetlands or quiet river segments.

Yes. SDI-12-compliant sensors run directly on Aquatos, pressure, multi-parameter sondes, radar level, all of it. Modbus sensors (RTU/RS485) integrate via the Type-0210 converter. Pulse outputs (water meters, tipping-bucket rain gauges) attach via the Type-0330 pulse counter.

On request we also support customers integrating their own sensors on the TerraTransfer platform — just get in touch.

SDI-12 is made for battery-powered environmental sensing: one shared bus for several sensors, very low power draw, long cable runs. It is the typical choice for pressure, multi-parameter and climate sensors on Aquatos loggers.

Modbus (RTU/RS485) is the standard in industrial sensing — radar level sensors or magnetic-inductive flow meters, for example. Modbus sensors draw more power; on Aquatos we integrate them via the Type 0210 converter, which only powers the sensor for the measurement itself, keeping it battery-friendly.

Rule of thumb: if the sensor exists in both variants, pick SDI-12. Modbus is right when an existing industrial sensor needs to be integrated.

Both are low-power cellular standards for IoT devices in licensed spectrum. LTE-M offers higher data rates and well-established international roaming — it is the default radio path of the Aquatos Web LTX. NB-IoT excels at building and below-ground penetration with even lower energy per transmission, at lower data rates.

In practice you don't have to choose: the Aquatos Web LTX uses LTE-M with automatic NB-IoT fallback. If LTE-M is weak at the site — say, a below-ground shaft with a cast-iron cover — the device switches by itself.

A submerged pressure probe always measures water column plus barometric pressure. A gauge (relative) sensor compensates mechanically: a vent capillary in the cable feeds ambient air pressure to the back of the diaphragm, so the reading is the water level directly. The sensors on the Aquatos Web LTX and mini work this way.

An absolute sensor — as in the Aquatos nano — measures total pressure including the atmosphere. Barometric pressure must be measured separately and subtracted; otherwise weather-driven swings quickly show up as 10–30 cm of apparent water column.

The advantage of absolute measurement: no capillary, so no kink or moisture risk in the cable and a more compact build — which is why the nano fits into a 1″ probe. The advantage of gauge measurement: directly compensated readings without a second measuring point.