How to Calibrate your Spreader

We’ve all heard that calibrating your spreader is important — especially when it comes to Ice Slicer.  But, how do you actually calibrate  your plows? Here’s a no-fail guide to help you get your calibration done.

Step One: Write down which truck you’re calibrating.  Don’t get lazy and think  that by calibrating one truck you’ve figured out the calibration for all of them.  It’s a fact that even if all your shed’s trucks are the same model, make and year — they’ll have different results. So, keep it organized, and download this handy calibration card for each truck in your shed.

Calibrating snow plow by measuring truck gates

Step Two: Let’s talk about truck gates.  Start by setting your truck’s gate to approximately 2 inches. Then, grab your measuring tape and walk to the back of your truck to see how high the gate actually is.  To measure correctly, measure from the bed of the trailer right up to the bottom of the rubber. Adjust the height until you get it right. Write down the gate opening size in your calibration chart.

Note: The size of a gate opening isn’t set in stone — it depends on what deicer material you are using.  

Ice Slicer logo

Here’s a quick tip. A lot of our Ice Slicer customers share that they typically leave their gate opening 1 -2 inches when using Ice Slicer.

Counting auger Rotations on a Snow Plow

Step Three: It’s auger time. Cut out a small square of paper and draw a straight arrow on it. Then tape (or add grease) to the square and stick it on your truck’s shaft with the arrow pointing up. This makes it easy to count the auger revolutions — every time the arrow hits 12:00 you know it’s rotated once.

Revving Engine for Snow Plow Calibration

Step Four: Grab a friend from your shed and have him sit in the cab. Make sure he sets the auger to “1” and the Spinner Circuit to “0”.   Stand next to the shaft while you have your friend (in the cab) rev the engine to 1,500 – 2,000 RPMs consistently. Grab a watch or a timer and count how many times the shaft revolves during the next 60 seconds.  Write down how many times it revolved on your calibration chart under “Control setting 1” and column “A”- now do the exact same process for each of your auger settings.

Note: Remember that column “A” is the Shaft RPM in a loaded plow. 

Tools needed to measure deicer

Step Five: Take a look at column “B” on your Calibration Chart — we are just about ready to fill this section out by measuring “discharge”. This step is really simple but you are going to need to gather a few supplies:

  • A Scale – you don’t need anything fancy, the kind you stand on to measure your own weight will work just fine.
  • A Bucket – put the bucket on the scale.
  • A Tarp – to catch any Ice Slicer
Measuring deicer on tarp

Step Six: Make sure your plow’s truck bed has the deicing material you plan on using while you plow. Then place your tarp under the spinner.  Turn the spinner off on your truck and keep the auger on a low setting.  Release the salt onto the tarp until your shaft does on full revolution. Gather all the salt that your truck released onto the tarp and put it into a bucket.  Place the bucket on a scale to measure the weight of the salt. Enter the weight in column “B” of the Calibration Chart.

Note: When you are filling out column “B” remember to record the weight on your scale in pounds not kilgrams.

Filling out a calibration chart for snow plow

Step Seven:  Let’s do some calculations.  Grab a calculator, or just use the one commonly found on your phone.Take a look at your Calibration Chart’s three columns: A, B & C.  So far, we’ve filled out A & B. To find “C” a.k.a the “Discharge per Minute” all you have to do is multiply A by B. Find “C” for all the controls settings 1 -10.

Want to Learn More?

There are plenty of calibration videos that can help you out.  In fact, that’s where we found the images above.  For more great resources, check out LTAP and for another great video, watch The City of Farmington Hills, Department of Public Works video here