Inversions are invisible, unless you have the tools to look
By Robin Booker | May 3, 2018
A tool designed to identify temperature inversions will help producers better understand when it’s safe to spray their crops.
Innoquest Inc.’s SpotOn® Inversion Tester is essentially a pole with a temperature sensor on one end and a readout on the other.
It allows producers to measure the temperature at two levels: one and three metres high.
The tool is one-metre-long so an operator holds it upside down to get a reading at the one-metre height, and turns it right-side-up to get a reading at the three-metre height.
“When it’s satisfied that it has both those temperature measurements, because it does have a sensor in there that tells you if you’re holding it right-side-up or upside-down.it then calculates whether there is an inversion present by comparing the two temperatures,” said Bill Hughes of Innoquest Inc.
If it’s warmer at the three-metre height than at one metre, it will display that a temperature inversion is present.
To achieve accurate air temperature readings, the temperature sensor is shielded, so readings are not affected by solar radiation.
Applications expert Andrew Thostenson from North Dakota State University has tested prototypes of the SpotOn Inversion Tester and he said he’s pleased with it.
Before the availability of a hand-held inversion tester, applicators had to look for indirect signs to detect inversions.
“We are looking at things like dust in the air, whether it hangs, smoke in the air, noise, frost or dew. These are all indirect results of an inversion.
“But really measuring an inversion in a field with some sort of hand-held device has not been available,” he said.
He said researchers from North Dakota State University have settled on the notion that if there is a 0.5 F inversion, spray applicators should be concerned….