When the GAC500 MT grain analyzer from Dickey-john arrived at our farm, my first thought was that it was bigger than I expected. With a footprint that is slightly smaller than a sheet of 8½- × 11-in. paper, it is more compact than the commercial testers you see at grain elevators. But I think it is still a bit too big for the combine cab. Because it comes with a power adapter, it would probably be okay to take out to the field for evaluating test plots. On our farm, the unit found a home on our front porch where it was handy to use and easy for the neighbors to see and comment on.
Everyone agreed that the all-steel construction looked sturdy, but I wasn't sure how durable the two-chambered grain cell would be during heavy use. I wasn't convinced until I had used the tester for several weeks. We didn't baby it at all, but the unit performed without any problems. So it passed the durability test.
Ease of use
One nice thing about the setup is that you don't need to weigh the sample on a separate scale. Just pour the grain in, strike it level, zero out and press the test key. Easy-to-read display instructions walk you through each step. This is a nice feature if you have someone operating the unit who doesn't necessarily do it all the time. Both my father and I were able to operate the unit correctly the first time.
Moisture percent is clearly visible. Test weight and temperature readout are smaller, though, and I found those numbers difficult to read without my bifocals. The downside of making the system foolproof is that it seems slow. It consistently took one minute to get a reading after starting the sample.
The GAC500 MT is very accurate on moisture. The wettest corn I tested was 21 to 22%. When I took my grain to the elevator, I found that the moisture reading was consistent with the elevator's more expensive testing equipment. Small hand testers I've used, including the new ones, just don't compare.
The unit reports test weight consistently heavier than the elevator's tester. You would have to keep this in mind if you were to use the test weight data for loading a truck to stay within legal weight limits.
The directions that come with this device say that grain needs to be within 20°F of ambient air temperature if you want accurate readings. I found that to be true, as grain coming straight out of the dryer showed unusually high moisture readings. Accuracy, especially for moisture, was consistently good on grain that was already dried and in storage.
At $1,450, this unit definitely seems worth the money to me. It compares favorably to the old Stinelite unit I own. And I'd say it's as good as some $5,000 units, at least for my purposes on the farm. An accurate tester is a worthwhile investment for anyone who dries his own grain, and the GAC500 MT appears to fit within that category.