The FreeWave water level monitoring solution is used to accurately measure the depth of water in any tank, river, dam, borehole, or pumping station. The depth being measured is based on the placement of the sensor, for a tank, this is typically in the bottom o the tank, for rivers the sensor is often mounted on a pole at a known reference height.

If you have irrigation systems that take water from a natural resource such as an on-farm stream or river, the water level monitoring solution will give you the data you need to remain compliant with water use regulations.

Measurements are taken every fifteen minutes and logged using onboard memory in the Fusion Mini. Every hour (satellite coverage dependent) these measurements are transmitted back to the cloud platform for processing, resulting in near-real-time alerts and trend reporting to help you identify changes in the environment being monitored.

Quick and easy to deploy, the solution does not require calibration and includes an onboard battery backup for uninterrupted operation regardless of the weather conditions

Installation Considerations

• The sensor is supplied as two cables connected by a junction box; a sensor cable and a signal cable
• The length of the sensor refers to the length of the sensor cable (between junction box and pressure sensor)
• The sensors can be ordered at pre-built lengths of 3M, 5M, and 10M but can be ordered at any custom length up to 200M
• The sensor cable is calibrated to the specific length by the supplier. It cannot be cut into a shorter length when a shorter sensor cable is required
• The junction box MUST remain dry at all times
• There are scenarios like a borehole where the borehole itself is 200M deep but there is water only in the last 25M. The sensor will be supplied with a 200M sensor cable but calibrated to 25M as the junction box must remain dry and out of the borehole
• The signal cable is an RS485 signal cable running at 12VDC
• The signal cable sold by FreeWave is sold in 2M lengths by default. A longer signal cable can be installed before shipping
• Signal cable can also be extended using RS485 extension cables. An example is here. This means that if you require a longer signal cable for a different use case after purchasing the sensor, you can extend it easily
• The signal cable can be several hundred meters long. The only consideration for long signal cable deployments is interference
• The actual hydrostatic pressure sensor should be hung vertically and ideally not quite at the bottom to avoid sitting in any sludge that might be present

Environmental Conditions

• The operating temperature of the Fusion Mini is from -20 C to 80 C. The storage temperature of the Fusion Mini is from -40 C to 85 C
• The water level sensor can be deployed up to a depth of 200m. This equates to approx. 300 PSI. There are some cold weather and ice implications which are detailed below
• Increases in water temperature can lower the specific gravity of water which will cause slight apparent fluctuations in water use that are not normally expected

Cold Climate Conditions

• In cold climates under 0 C / 32 F, lithium batteries will not charge when the solar panel receives sunlight. This is due to a restriction imposed by the battery manufacturer. In cold climates, charging a battery in cold weather can lead to lithium metal plating forming on the anode of the Fusion Mini leading to a potential battery short and failure
• In cold climates under 0 C / 32 F, lithium batteries have decreased performance and will discharge quicker than normal
• In environments where the tank liquid can freeze, this can affect the reported tank depth. While the supplied hydrostatic pressure sensor can be custom-built up to 200m depth which equates to 300 PSI, ice can start at 25,000 PSI. There may be some initial erratic readings after the liquid has thawed
• In snowy conditions, the panel can get covered in snow and the Fusion Mini will not charge. The snow covering the panel must either be removed manually or wait for ambient temperatures to rise to melt the snow. There is research being conducted on special coatings for the solar panel to reduce/eliminate snow build-up. You can view more here: https://news.umich.edu/spray-on-coating-could-make-solar-panels-snow-resistant/. Please note: These are not commercially available as yet.
• While the standard Fusion Mini is battery-powered with solar charging, there are options available for either external battery support or utility-supply power support for colder climates.
• If the Fusion Mini is configured for external 12v DC input, it cannot be used with a solar panel.  You must supply the 12v DC as a continuous supply and provide charge to the 12v system through a separate solar array and charging system. This type of configuration is common when the Fusion Mini is being powered along with other equipment from a larger power source or exclusively from the battery in situations where solar is not an option. 
• Should you wish to discuss external battery support or utility-supply power adapters, please contact the team at FreeWave Support who will be happy to assist.

Days of Autonomy

Defined as the number of days that the battery can supply the device and associated sensor power loads without any support from the solar panel.

• The Fusion Mini, when used as a water level monitoring solution with a single water level sensor, will have a minimum of 7 days of autonomy. 
• In cold conditions (below 0 C / 32 F) the days of autonomy can be reduced by as much as 60%.

Specifications

Full specifications can be found here: IIoT Water Level Solution Specifications – FreeWave