Are the spreaders on your snowplow trucks calibrated for the season?  If not, you probably don’t dial in the scope on your deer rifle either, right?  You don’t balance the speakers on your home theatre system?  Do you check the internal temperature of the center cut pork chops before they come off the grill?  Hmm, but you don’t calibrate your spreaders?

These days, many salt spreaders have advanced control units to meter out the salt (and/or sand) placed on the roadways during winter storms.  These are key to containing your costs for salt and minimizing environmental harm.  However, those advanced systems aren’t controlling anything if they aren’t calibrated to the mechanical tools at the rear of the truck.  You have to calibrate your spreaders.  You just have to.

Our instinct, generally speaking, is to put down more salt than is necessary.  The result is spending more money than necessary on salt and the excess material can create damage to the environment.

Whenever you have a new spreader or new controls, you need to perform a calibration.  And ideally, you should calibrate each spreader prior to the beginning of each season.  In a demanding season, another calibration part way through is smart, also.  If you change something in the hydraulics or the auger, if you change the battery or modify the gate setting or opening, a calibration is warranted.

Simply put, if your spreader is not calibrated, you don’t need those fancy and expensive controls in the cab…because you really don’t know how much you are putting down anyway.  Save the money on those expensive gizmos so you can make up for all the money you are probably wasting on salt that isn’t being put to good use.

The good news is that calibrating spreaders isn’t particularly hard.  Oh, it’s a bit tedious, but that’s not unique in our line of work.  If you are unsure of how to calibrate your spreaders, we do cover it briefly in our Winter Maintenance training workshop, so look for our next offering of that course.  But there are very good training videos available online as well.  Bear in mind that your type of equipment and setup may be a little different than what you see, but the basic concepts are the same.

One such pair of videos from North Caroline DOT begins in Part 1 with the removal of the tailgate and installation of the V-box spreader, while Part 2 focuses on calibrating that type of spreader.  You will also notice that the demonstration crew is mindful of safety precautions as they install the equipment and perform the calibration.

Another online resource from the City of Farmington Hills, Michigan shows an approach to calibrate a tailgate spreader.

After watching these videos, or others you can find online, you will see that calibration is not very difficult and takes a relatively short time.  You can use a chart like the one developed by the Salt Institute below and you’ll have all the information you need to set your controllers.  Then, you will actually be able to control how much salt (and/or sand) you are actually putting down on the roadways.

The Delaware T2/LTAP Center’s Municipal Engineering Circuit Rider is intended to provide technical assistance and training to local agencies and so if you have winter maintenance questions or other transportation issues, contact Matt Carter at or (302) 831-7236.

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