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OPI Introduces Moisture Sensors

OPI-Integris, which 25 years ago brought western Canadian farmers the first temperature sensing cables for monitoring grain condition inside the bin, has this year introduced a monitoring cable that provides a reading of both moisture and temperature of stored crops.

The combination OPI-Integris moisture/temperature monitoring cable appears similar and operates similar to the straight temperature cable, but adding the moisture reading is a “huge leg up” for farmers looking to protect the quality of crops while in storage, says Dave Crompton, OPI-Integris founder and company CEO.

“Temperature is one indicator, but being able to determine the moisture level of stored crops provides considerably more information to producers,” says Crompton. “The old saw is that moisture is money. Grain is sold by weight, so the objective is to have crops at safe moisture levels for storage, but at maximum allowable moisture content for marketing”. Technology behind the moisture sensing cable, earned the Calgary-based OPI-Integris an award from the American Society of Agricultural and Biological Engineers earlier this year.


Aeration systems on grain bins, for example, are used for two primary purposes — to get air flow through the stored crop to reduce heat, and also, if needed, to lower moisture content by a couple percentage points to achieve safe moisture storage (depending on the crop about 14 per cent for short-term and 12 per cent moisture for long term). Some larger bins can be outfitted with drying units to actually use the bin as a grain dryer.

“These new moisture cables, will eliminate the guess work of moisture levels in stored grain,” says Crompton. “The cable is accurate to within about one per cent moisture. And moisture can have a huge impact on crop value. Moisture itself is not a quality parameter, but if stored grain is too high in moisture it can lead to overheating and mould, as well as contribute to disease and insect development in stored crops.”

Crompton says in hopper or flat bottom bins up to 24 feet in diameter one moisture/temperature cable, suspended in the centre of the bin is sufficient to monitor bin conditions.


In larger bins, he recommends a combination approach that includes one moisture/temperature cable in the centre of the bin and then two or three more moisture/temperature cables on the inside perimeter of the bin, along with two or three of the standard straight temperature sensing cables.

If farmers already have OPIIntegris (brand name StorMax) temperature sensors installed in bins, again on the smaller bins it is matter of replacing the straight temperature cable with the new combination cable. In larger bins, Crompton says producers should swap out some of the straight temperature cables and replace with the combination cable.

The combination moisture/ temperature cable costs about 50 per cent more than a straight temperature sensor. That brings the suggested retail price of the combo cable to about $600 each.

Depending on the size of the grain storage system there are two ways to monitor moisture/ temperature cable readings. With smaller systems farmers can stand next to a bin to use a hand held StorMax monitor with digital display that shows both moisture and temperature levels. And with larger systems, or for producers who live some distance from grain bins, an Integris Pro monitoring system can be installed which links readings from sensor cables to farm office computers, whether you are just down the road, or two provinces away.

“It is an excellent insurance and management feature,” says Crompton. “You can guess at what moisture levels are in the bin, or you can invest in technology that will provide a much more accurate measure. If you can increase the value of stored crop or on the flip side reduce the risk of spoilage due to high moisture, the sensor equipment pays for itself very quickly.”

OPI-Integris has an established dealer network in Canada and the U.S. For more information on company products visit their website at:

LeeHartisafieldeditorforGrainewsat Calgary.Contacthimat403-592-1964orby emailat [email protected]

About the author

Field Editor

Lee Hart

Lee Hart is editor of Cattleman’s Corner based in Calgary.



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