Span Engineering’s Sentek solution!

16 February 2023


Here’s a case study submitted by Span Engineering, a client who recently deployed some Sentek EviroScan soil moisture probes.

If you want to offer remote control or monitoring of your product, you can call Span Engineering. Span offer expertise and their own platform called “Doover” to help you do this. “Doover” is the “App-in-a-box” for your product. More information can be found on our website:

Span recently worked with HydroTerra to source Sentek EnviroScan soil probes in an automated composting project with project partners Radicle Agriculture.

Did you know that 30% of Australia’s methane emissions come from organic material going into landfill. Synthetic fertilisers compromise soil fertility, have a significant carbon footprint and are becoming increasingly expensive and hard to source.Industrial-scale composting provides a solution for both of these problems.

Traditionally, composting is hard & dirty work – requiring lots of machinery & man hours for regular turning, and creating noise & odour. Span Engineering & Radicle Agriculture have created the “High Efficiency Aerated Pile System” (HEAPS) in response to this problem.

The HEAPS system is a scalable, autonomous composting system that does not require turning for aeration, but instead aerates the pile through pipes under the pile. Water is applied through sprinklers or drippers on top of the pile. Once a pile is constructed, it can be covered and left for the HEAPS system to monitor and manage the aeration, temperature and moisture, until the pile is finished composting. The HEAPS system continuously collects data for each pile including oxygen levels, temperature, moisture content & PH.

The data collected is used by the controller to manage the aeration and watering of each pile, to send alerts if something is wrong, and is collated into a report after each pile is finished for quality control and compliance. The centre of a composting pile is an extremely harsh environment for sensitive electronics. It is a very wet and highly corrosive environment with temperatures above 80 degrees celsius often sustained for weeks. HydroTerra-sourced Sentek soil probes were integrated into this HEAPS system to measure the temperature & moisture through different levels of these compost piles, to better understand how drying fronts were moving through the centre of these piles.

Sentek EnviroScan probes were chosen for their durability and ability to provide customised arrangements of sensors along the length of a probe. Hydroterra were prompt and professional to work with, and the supplied probes returned valuable data in this demanding application. We look forward to working with Hydroterra and Sentek on further future projects.

More information can be found on the following websites: