Ensuring Accurate Calibration of your Moisture Tester

Moisture testing is of critical importance in the harvest, storage and trading of grain. Inaccurate moisture readings can lead to spoilage if the grain is too wet for storage. Grain that is sold too wet can also lead to moisture shrinkage as well as extra cost for drying. All of this can lead to decreased profitability.

If you’ve invested in a moisture tester, make sure you’re getting accurate readings of your grain’s moisture content. A paper published by the Iowa State University lists several useful pointers for getting the most out of your moisture tester:

Take a good sample

Make sure you take a representative sample for testing. If sampling in the field, harvest a small area and then take a sample from the shelled grain. If this is not possible, take the grain from several plants and mix these together. For grain that is on a vehicle, it is best to take a sample across the grain stream while it is being unloaded. If not feasible, samples can be taken by probing from at least 2 areas in the bin, avoiding the center and sides. It is not advisable to take a sample from just the surface of the bin.

Using your tester

Check that the batteries are working well, and change them regularly. Read the manufacturer’s instructions carefully and determine whether the machine compensates for temperature. For example, cold grain will cause low readings. If your tester does not compensate for temperature, you may need to add several degrees to your reading.

In general it’s best to avoid sudden changes of temperature. For example, taking cold grain into a warm room can cause condensation that can lead to erroneous readings. Allow cold grain to warm thoroughly in a sealed container before taking moisture readings. Conversely, let hot grain cool slowly before testing.

Since repeated testing of the same sample will always result in slight variations of the readings, a good practice is to test each sample three times and then average the results.

Check the accuracy of your moisture tester

If your state’s local department of agriculture inspects and certifies elevator moisture testers regularly, you can take this opportunity to check the accuracy of your tester. Using a set of samples at various moisture levels, take readings with your tester and compare it with a reading of the same set of samples taken by the elevator moisture testers.

Or better yet, send your moisture tester to a qualified service center for servicing and calibration once a year. AgPoint Precision is a manufacturer, distributor and service center for testing and grading equipment for the grain, feed and seed industries.  We service a range of brands including Count A Pak, Seedburo / Burrows, Motomco, Dickey-John, Doran, Ohaus and Delmhorst. Contact us today. Our small staff have decades of experience in the seed counter and moisture tester lines.