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Best Grain Moisture Tester [TOP 5 REVIEWS] is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to As an Amazon Associate this site earns from qualifying purchases.

best grain moisture detector

Testing the moisture levels of your grain stock is very important. To ascertain the overall health of the grain, and to ensure that the storage conditions are optimum you need a reliable and accurate way of measuring.

And clearly, the best tool for the job is a grain moisture tester.

There’s a number of models on the market, however, and deciding which to buy can be confusing.

Best Grain Moisture Tester

Best Overall: Dickey John MiniGAC, Grain Moisture Tester

Grain Moisture Tester, Handheld
  • Price For: Each Type: Handheld Interface: Touch Pad Number of Grain Calibrations in Memory: 20 Ambient Humidity Range: 0 to 95% Temp. Differential: 36 Degrees F Cycle Time: 16 Sec. Item: Grain Moisture Tester Sample Size: 250 Grams Depending on Grain Number of Languages: 10 Ambient Temp. Range: 41 to 113 F Moisture Content: 5 to 45%, Grain Dependent Display: LCD
  • Power Source: 9v Battery Grain Temperature: 32 Degrees to 122 Degrees F Manufacturers Warranty Length: 1 yr. Country of Origin (subject to change): United States

Overall, the Dickey John is a top-quality grain tester that is ideal for those looking for an affordable, portable option.

Capable of testing over 450 calibrations, versatility is the heart of the MiniGac. Our top pick grain tester for 2020, for good reason.

Best Budget: MT-16 Grain Moisture Tester

Agratronix MT-16 Grain Moisture Tester
  • High Performance. Direct readout for 16 different grain scales. Each scale adjustable to match local elevator
  • Efficient. Automatically averages up to 99 test results
  • Improves Accuracy. High-frequency capacitive circuit with accurate temperature compensation circuit
  • Convenient. Protective carrying case with shoulder strap included65
  • Farmer's Choice. Used reliably by the USDA Federal Crop Insurance Field Office

The AgraTronix MT-16 Grain Moisture Tester is our best budget choice because it balances great features and accuracy, with an affordable price point.

Yes, there are only 16-grain types available for measurement here, but for many of us, that will fit the bill. Highly recommended.

Best Industrial Use: Dickey John GAC500XT Grain Moisture Tester

Grain Moisture Tester,Semi-Portable
  • Category: Lab Supplies -- Agricultural Testing

The Dickey John GAC500XT is a top-quality grain moisture tester for those looking for elevator-style power for their farm.

Yes, the price point is high, however, it is understandable considering what’s on offer here.

Grain Moisture Tester Reviews

There are factors such as the type of grain that the tester can measure, clearly the more versatile model you can buy, the better.

There’s also the issue of portability; will you be taking measurements while out in the field or back at base? In order to do the former, you will need to ensure that the moisture tester is battery powered.

There are also scale and accuracy levels to think about. A premium machine will come close to matching grain elevator-style testing capabilities.

In this review round-up, you will find a selection of top-rated grain moisture tester, backed up with verified customer reviews in tandem with intensive product research and analysis.

These are the results…

1. BEST OVERALL: Dickey John MiniGAC, Grain Moisture Tester Review

Dickey John MiniGAC

The MiniGAC from Dickey John is our top pick grain moisture tester for good reason. Not only is the price point more than competitive, but it also contains all the features you need for reliable, yet fast and accurate grain testing.

The expertise is very apparent mind you; with over 50 years in the testing space, Dickey John has been building top-quality sensors, controllers, and monitors for agricultural, public works, and analytical markets.

And whether you need to test grain moisture for harvesting, storing, or trading, the MiniGac can be used. It’s extreme portability, and handheld nature makes it perfect for out in the field.

Choose from over 450 calibrations that are available, (with 20-grain calibrations)

There are some impressive features built-in of course, (hence being our top pick). The easy to use unit is controlled via a menu-driven operating system.

The automatic temperature compensation is a very handy feature as is the internal scale. The latter means no pre-weighing is required.

For calibration loading, there is USB compatibility. Furthermore, the no screw cap avoids any damage happening to the grains once placed inside the machine.

Finally, the reliable Dickey John throws in 1 year’s manufacturer’s warranty.

Package Includes
  • Mini GAC
  • loader 9-volt battery
  • instruction manual,
  • A 1-year manufacturer’s warranty.
Product Specifications
  • Measure Method: capacitance, conductance, internal scale, temperature
  • Moisture Range: 5-45%(depending on grain type)
  • Grain Temperature: 32-122 Degrees F (0-50 Degrees C)
  • Temperature Difference: 36 Degrees F (20 Degrees C) Instrument to grain sample
  • Temperature Compensation: Automatic
  • Grain Type: Whole Grain, no sample preparation
  • Sample Size: 1 Pint (0.47 L)Display: LCD (106×56 pixels)
  • Measured Parameters: moisture, grain temperature
  • Calibrations: 20-grain calibrations (choose from over 450 calibrations that are available)
Pros of the Dickey John MiniGac Grain Tester
  • Easy to use, menu-driven interface
  • Includes internal scale (no pre-weighing required)
  • USB compatibility for loading up calibrations (450 available)
  • Automatic temperature compensation
The Cons
  • Doesn’t work with newest Windows or Mac operating systems
  • Instructions could be more detailed

2. AgraTronix 05100, MT-PRO+ Portable Grain Moisture Meter Review

AgraTronix is another well-known brand that has been manufacturing grain testers for a number of years.

While not as easy to use as the MiniGac, the 05100 MT-PRO is still portable in design, and suitable for harvest and storage work; (i.e you can take it to the grain, rather than the other way around).

The moisture range is good; the unit can detect as little as 5% moisture right up to 40%.

The 05100 also measures the temperature of course. Here the range is 32° to 113°F (0° to 45°C).

All well and good I hear you say, but what about accuracy. This is where AgraTronix has a proven track record across their product output.

With repeatability & accuracy: ± 0.5% (normal moisture range for stored grain); this is a unit you can rely on for accurate measurements.

Another great feature is that the unit is able to automatically average the selectable number of tests.

Not only that, the inbuilt memory means that the average calibration for all grains tested can be stored.

Much like our top pick from Dickey John, there is a USB port that enables you to store data as well as feed firmware and diagnostic updates into the machine.

The diagnostic option is there to assist users in diagnosing issues should faults occur.

A total of 40 different grain scales are offered direct readout, (more on that in the tab below).

List of Grain Scales
  • Alfalfa
  • Barley
  • Beet
  • Buckwheat
  • Canary Clover
  • Purple Clover
  • White Corn
  • Dactyl
  • Fescue
  • Flax (Linseed)
  • Lentils
  • Millet
  • Mustard
  • Navy Beans
  • Oats
  • Peanuts
  • Spanish Peas
  • Fodder Peas
  • Green Peas
  • Yellow Phleum
  • Popcorn
  • White Popcorn
  • Yellow Rapeseed
  • Long Rice
  • Medium Rye
  • Rye
  • Grass
  • Safflower
  • Sorghum
  • Soybeans
  • Sunflower Oil
  • Stripe
  • Triticale
  • Durum Wheat
  • Hard Red Spring Wheat
  • Hard Red Winter Wheat
  • Soft Red Winter Wheat
  • White Wheat
Package Includes
  • MT-PRO+ Grain Moisture Tester;
  • Replacement Cap (06061);
  • Carrying Case with Shoulder Strap (06053);
  • 5′ USB Cable (06067).
Pros of the MT-PRO+ Grain Moisture Tester
  • Moisture range: 5% to 40% depending on grain tested
  • Temperature range: 32° to 113°F (0° to 45°C)
  • Repeatability & Accuracy: ± 0.5% in normal moisture range for stored grain
  • Direct readout for 40 different grain scales
  • Automatically averages selectable number of tests
The Cons
  • Some users have had problems calibrating the unit to the local grain elevator

Bottom Line

Overall the MT-PRO+ Grain Moisture Tester is a very capable machine. With its high accuracy levels and portable design, this certainly does the job while out in the field.

While not as versatile as our top pick from Dickey John, this is still well worth considering.

3. AMTAST Grains Moisture Meter Smart Grain Moisture Tester Review (Test 25 kinds of grains)

We move further into the budget range options now, with a grain tester that is much cheaper than the 2 we have reviewed so far.

However, the trade-off when opting for a lower-priced model generally comes down to the number of features included, (and rightly so).

With the AMTAST grain moisture tester, you will be able to measure the levels of 25 kinds of grain, (see tab below for the full list).

That being said, if the type you will mainly be working with is listed, there is no reason why this unit could not be the option for you.

Accuracy levels are good, and as with the majority of the testers that have made our top 5, the design is portable too.

Moisture and temperature readings can be taken, (I nice feature with the AMSTAT is that both can be taken at the same time).

This makes for greater efficiency as you work. The AMT65C actually takes very fast readings as well. Data is shown via the small display, which is backlit for use in low light conditions.

Should you need there is also the ability to insert an optional external temperature sensor.

One complaint would be the occasional fault of a loose connection between the cable connecting the screen to the main motherboard.

The manufacturers provide a solution on how to fix this, however.

List of Grain Scales

Cocoa Beans, Rapeseed, Wheat, Spring Barley, Field Bean, Corn, Winter Barley, White Oats, Buckwheat, Black Oats, Hard Wheat, Lupine, Rice, Paddy rice, Soybean, Sunflower Seed, Corn (high), Sesame, Cotton Seed, Cotton Parker, Canola, Peanuts, Watermelon Seed, Coffee Beans, Radish Seeds.

Pros of the AMSTAT AMT65C grain moisture tester
  • Display with backlight
  • Can display grain moisture and temperature same time
  • Can insert optional external temperature sensor
  • Quick fast reading with accurate data
The Cons
  • The loose cable between the screen and motherboard is a nuisance should it happen to you.
  • People have had problems contacting support at AMSTAT.

Bottom Line

For a budget option, the AMSTAT AMT65C is a great little grain tester. With a total of 25 types of grain that can be measured, this is one of the least versatile testers in our top 5. However, you do get what you pay for.

The potential fault with the screen cable is something the guys at AMSTAT need to solve. That being said, the fact they have been transparent about the issue is commendable.

4. BEST BUDGET: MT-16 Grain Moisture Tester Review

Our top choice budget grain moisture tester is the MT-16 from AgraTronix.

In short, this is the toned-down version of the 05100 that we reviewed above. Smaller, more portable but just as accurate this is a fantastic little unit for the price.

As with the AMSTAT the trade-off when buying a lower budget machine is the level of versatility.

Here, only 16 different grain scales can be read. However, if after checking the specs the ones available apply to your needs, the MT-16 will not disappoint.

Each of the 16 scales adjustable to match the local elevator.

The averaging is also impressive, with the unit capable of averaging up to 99 test results.

The moisture measurement range is good, starting at 5% and reaching 40%, (depending on grain tested). The temperature range is also impressive with the machine able to read outputs between 32° to 113°F (0° to 45°C).

We already mentioned the accuracy levels, but let’s take a closer look at that. Repeatability & Accuracy come in at ± 0.5% (in normal moisture range for stored grain).

The manufacturers state that the high-frequency, capacitive circuit is one of the main reasons overall accuracy has been improved so much.

List of Grain Scales
  • 1% moisture.
  • Corn 5-21%
  • Corn 17-40%
  • Wheat-soft
  • Wheat-hard,
  • Soybeans
  • Sorghum
  • Oats
  • Canola
  • Barley
  • Rye
  • Beans Paddy Rice
  • Flax
  • Safflower
  • Sunflower-oilseed
  • Sunflower-confect
  • Arbitrary Scale.
Pros of the MT-16 Grain Moisture Tester
  • Affordable price point
  • Accurate readings of both moisture and temperature
  • Scales are adjustable to the local elevator
  • Robust, yet portable design
The Cons
  • Only 16 different grain types can be measured

5. BEST INDUSTRIAL: Dickey John – GAC500XT, Grain Moisture Tester Review

From budget-friendly to time to speak to the bank manager. Our top pick for industrial-scale use is this excellent GAC500XT from Dickey John no less.

The features available here warrant a high price point, (we’re talking several 1000 dollars now), however, anyone looking to install the power of elevator-quality testing on their farm, will know that the ability does not come cheap.

That being said, this is still a semi-portable model that can be carried from site to site with relative ease.

The fact it can be powered using a DC inverter or cigarette lighter only adds to the convenient nature of the design.

The Dickey John GAC500XT enables the user to analyze grain moisture, temperature, as well as weight, meaning versatility is also very good.

The unit is easy to use too. More than 450 calibrations are available for download. However, only 16 can be stored at any one time.

As long as you have the correct calibration loaded, you simply choose the appropriate one for the grain you are measuring, load up the hopper and press to initiate the test.

Pros of the GAC500XT grain moisture tester
  • Grain elevator quality testing at a competitive price point
  • Easy to use
  • Portable, can be powered using a DC converter or a cigarette lighter port
  • Over 450 calibrations available for download
The Cons
  • Only 16 calibrations can be stored at any one time
  • Much more expensive than other options in our top 5

How to use a grain moisture tester?

Once you have bought your grain moisture tester, you will need to know how to use it. Here’s a short guide to help…

Read the Manual

This may seem like an obvious statement to make, but as grain tester devices vary in how they are operated, reading the manual should be your first port of call.

Your grain moisture tester’s compensation method is an important variable to understand, as sample temperature impacts the accuracy of your reading.

Beyond that, just simply knowing how to access your calibrations and upload new ones is required if you want to get the best out of your device.

Watch the condensation levels

When using a grain moisture tester, you need to be able to compensate for high condensation, as the presence of condensation leads to inaccurately high readings.

One of the best ways to avoid issues with condensation is to allow hot grain from a dryer to cool slowly. You can leave it in a sealed container and ensure that any visible condensation has dissipated before you take any readings.

Furthermore, rapidly cooled grain can cause inaccurate readings with moisture testers, so it is best to allow the test sample to cool naturally to room temperature.

Controlling the samples

Another way of ensuring accurate readings is to ensure that the samples are not too cold when you test them. The cold grain will give lower moisture readings, so should be warmed to ambient temperature before being tested.

Ensure the device is fully charged

If your tester has low batteries it will likely impede the accuracy of your readings. Most devices have a low battery indicator, however, carrying a spare when out in the field can be helpful and prevent any unnecessary delays or worse still, inaccurate readings.

How to obtain the best (most representative) grain sample?

There are a few steps you can take to help ensure you have representative samples for testing. Let’s look at a few of them now…

Harvested Grain

First is the grain that has come straight from the combine harvester. For this, you can start by handpicking a shell from several plants within the area that you intend to harvest. This will give you a sweeping sample of the grain from its natural setting.

Unloaded Grain

You should also take a sample from the flowing grain during the unloading process. Hold an empty container beneath the grain stream at 50-bushel intervals.  Mix this grain into one container and then take a sample from that.

Binned Grain

Finally, you need to take samples from your silos. These should be taken at various depths and locations, using a 6 -10’ probe if possible. You will need to be careful to record the sample location carefully, in order to track bins where moisture is taking hold.

What happens if my moisture testing is inaccurate?

Accurate grain moisture testing is very important. Failure to take correct readings can be time-consuming and expensive. Here are 3 reasons you will want to ensure that your readings are as on point as possible.

Spoiled Grain

First and foremost, grain with too high moisture levels will mold. If large quantities of grain are spoiled, it can cost you a lot of money.

Drying costs

If you have harvested grain when there too much moisture is present, you will be forced to increase the drying methods in order to keep the product from spoiling. The energy and time invested in this will only reduce your profit margins.

Over drying

If your measurements are inaccurate and you end up over-drying the grain, you will reduce the quality of the product. There is also the issue of the wasted resources as mentioned in point two. Overall, it will end up being an inefficient use of your heating and manpower.

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