AutoSalt (AQAc™)

Base Automated salt dilution system includes:

• AQAc custom control module
• Creek Pressure Transducer (PT)
• Reservoir PT
• Left Bank and Right Bank T-HRECS self-logging EC-T probes with D-Cell Battery bank, and LoRa for long-range radio comms
• Proprietary salt injection system
• 3 year Basic license to the “Salt Portal” salt dilution database management system and Rating Curve (RC) development tools
• 3 year warranty

Automated salt injection system that does the work for you.

It can be difficult to obtain a full range of flow measurements for your hydrometric rating curve. Resources are often wasted visiting sites at similar flow conditions. At Fathom Scientific, we’ve been developing the Automated Q Acquisition (AQAc…a.k.a. AutoSalt™), since 2008 to address these and other challenges. The AutoSalt (300L Tank and Stand) System consists of a control system, 300 litre brine tank and custom aluminum stand, Creek Pressure Transducer, 2x T-HRECS self-logging EC-T probes, and a proprietary salt injection system. Systems have been installed at >20 locations around the province of BC since 2008 and collected hundreds of automated discharge measurements.

How Does it Work?

The system works by first sensing the water level in the Creek. This is essentially a redundant water level sensor to support an existent Hydrometric program. The AQAc then decides to inject brine based on a combination of logical rules, preferably injecting brine on the falling limb of a hydrograph. Alternatively, a Regular Injection Interval can be set. Measurements can also be triggered via Telemetry. EC-T data is relayed back to the Control module via LoRa radios, as well as logged continuously at the D/S Temperature – High Resolution Electrical Conductivity Serial (T-HRECS) device EC-T sites. Injected brine volume is measured by three independent methods. Due to the high resolution and sensitivity of the T-HRECS EC-T sensors (and the paired U/S T-HRECS) we can use very low salt doses and still achieve low SDIQ uncertainty. Typically we set the brine [NaCl] to 20%, and aim for 1 litre of brine per m³/s. Tanks come in 200 and 300 litre sizes. This implies we can measure between 200-300 cumulative m³/s per visit, i.e. 10 measurements of 20 m³/s (for the 200 l tank) or 200 measurements of 1m³/s. Of course, in reality it will be a range of flows.

Systems have been installed at numerous locations around the world including Canada, New Zealand, Germany, UK, France, Italy, Japan,  Sweden, and Canada for agencies such as NIWA, TUM, Helmholtz Institute,  DREAL, UKEA, SMHI, and WSC, along with several hydropower and mining operations.  See the “AutoSalt Gallery” for a selection of projects.