Computer algorithm monitors moisture

Manitoba entrepreneurs are using a basic principle of physics, that light behaves differently in water, to measure moisture levels inside grain bins.

While the technology remains at the proof of concept phase, scientists behind the system think it could compete with existing methods to measure grain moisture content.

“The current technology is basically a temperature sensor on a wire that’s strung inside the grain bin. When the grain gets too moist, it sprouts and the temperature goes up,” said Colin Gilmore, co-founder of 151 Research Inc., a Winnipeg technology company.

“(Our) technology will actually sense the moisture content. So, hopefully before the grain sprouts, you can get in there and fix it.”

Gilmore and his colleagues at 151 Research are designing a prototype system where a series of antennas inside a grain bin send electromagnetic signals back to a computer.

The signals provide information on the permittivity of the grain, which a computer algorithm analyzes to devise a three dimensional map of moisture levels inside the bin.

“It (permittivity) is basically a measure of how an electromagnetic wave travels through a material,” said Gilmore, who has a PhD from the University of Manitoba, where he specialized in electromagnetic imaging. “It’s directly related to the speed of the wave inside of (a medium)…. And it’s related to how the wave is decaying inside of the media.”

Put another way, the Princeton University website defines permittivity as “the measure of how much resistance is encountered when forming an electric field inside a medium.”

In the case of grain inside a bin, the amount of water within the grain affects the permittivity. If it’s possible to measure permittivity, that data can be used to calculate moisture content.

“Light does different things inside water,” said Gilmore, whose Research 151 colleagues also have PhDs from the U of M. “This is the same physical parameter but we’re just operating at a very different frequency range on the electromagnetic spectrum.”

The leaders of 151 Research, in collaboration with TRTech, a technology commercialization company, Intragrain, a grain bin monitoring company in Regina and Joe LoVetri, who runs the Electromagnetic Imaging Laboratory at the University of Manitoba, are finalizing the details of a prototype system to measure moisture content.

They plan to install the prototype in September at the CWB Centre for Grain Storage at the U of M.

Describing what it looks like, Gilmore said the system is fairly simple.

“What we’re dealing with right now is like an old car antenna. Just a wire sticking out of a piece of steel.”

Once inside the bin, the antennas transmit signals to a computer.

“Data points are collected and fed into a computer algorithm that makes the image. The meat of this technical magic… is in that computer algorithm.”

In late August the federal government provided approximately $300,000 for the project to help commercialize the technology.

Gilmore said they are using the money to prove the technology works and to design a system that is economical for farmers.

The technology is pricey at present because LoVetri and his team at the Electromagnetic Imaging Laboratory are focused on potential medical applications.

“This technology isn’t widely used in the biomedical industry. It’s still mostly in research labs,” Gilmore said.

“The primary application that has been looked at, for many years, is for breast cancer detection…. That has been the driver of the technology, from the biomedical side.”

Gilmore and his collaborators will simplify the basic concept of that system and apply it to grain bin monitoring.

“We’re fairly confident we can bring that cost down to be competitive with the temperature sensing wires.”

About the author


Stories from our other publications