Introduction
The harvest season is one of the most important times of the year for farmers across the world, and a good harvest can make or break the year. Most farmers and industry experts would agree that monitoring grain moisture content throughout the harvest season is essentially non-negotiable, as moisture content can be the single most critical influencer of overall grain quality, and a financially successful harvest. Suboptimal moisture content in grain can reduce its market value, potentially contaminate existing grain stores causing safety concerns, and require additional effort and resources to bring it to market, thus reducing margins.
Moisture meters have long been a key tool utilized by farmers to provide real-time information on grain before, during and after harvest. Farmers have a relatively wide variety of moisture meters to choose from in the market, most falling into one of two categories – handheld or benchtop/laboratory models. While handheld moisture meters have distinct advantages over benchtop units, namely their price, portability and lack of complexity, they also present distinct challenges and drawbacks, along with potential risk, which may outweigh the monetary savings for many users.
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When deciding which model is best for you and your operations, ask yourself the following questions:
- Is price the most significant factor in your buying decision? If so, handheld meters are most certainly the best option for you. Priced at a fraction of the cost of benchtop units, handheld meters are a great choice for users with small budgets that are willing to sacrifice functionality and/or accuracy to stay within their budget.
- How much do you value accuracy and consistency? Benchtop moisture meters tend to be more accurate, with handheld moisture meters often resulting in biased low results – meaning your sample has more moisture than the reading is indicating. Further, handheld capacitance meters are about 1.5 to 2.0 times as variable as benchtops models at the same moisture content1. If accuracy isn’t your top concern, a handheld moisture meter may meet your needs, but be careful, as a 1% difference in moisture content could have a significant impact on your harvest.
- How often are you willing to calibrate? Calibrations are vitally important to maintain accuracy, and failure to properly calibrate your testing equipment is a recipe for disaster. Many handheld meters require frequent, even daily, calibration using calibration samples or external reference methods. Benchtop units tend to require calibration updates only once per year.
- Are temperature and humidity controlled during sampling? Calibrations on handheld moisture meters tend to be temperature dependent, typically around 77°F/25°C. Deviations from this temperature can produce inaccurate readings, and users of handheld instruments typically need to wait for grain temperatures to equilibrate before testing. Similarly, as most handheld meters measure the electrical properties of grain, environmental humidity can cause changes in the properties of the grain, further impacting accuracy. Benchtop units typically have a much higher tolerance to temperature and humidity fluctuations.
- Do you plan to analyze more than one type of sample? Handheld moisture meters are typically only utilized for one type of grain, such as wheat, corn or soybeans. If you will only need to measure one type of grain, handheld meters should meet your needs. However, investing in a benchtop unit utilizing the Unified Grain Moisture Algorithm (UGMA) enables the accurate analysis of a wide range of crops on the same instrument, future proofing your investment.
- How many people will be utilizing the moisture meter, and are they trained appropriately? User error is one of the primary contributing factors to poor accuracy, and inconsistencies between users can further exacerbate this problem. Error can be introduced by inconsistent positioning of probes on handheld units, or through improper subsampling, which can lead to the analysis of an unrepresentative sample. Benchtop units remove much of this uncertainty and variability through much fewer user inputs.
In the choice between handheld and benchtop moisture meters, the decision often comes down to price versus accuracy. If you can budget for a benchtop unit, the increased accuracy can greatly reduce the risk of grain spoilage and maximize your margins, and depending upon your operations, may even pay for itself after one harvest.
If you’ve decided on a benchtop moisture meter, Perten’s AM 5200-Farm offers the convenience, accuracy and speed that modern farm operations demand. One of the key differentiators of the AM 5200-Farm versus handheld units is its ability to test both hot and cold grain samples, enabling the fast analysis of grain samples at harvest, pre- and post-drying, and throughout the storage process. Utilizing a benchtop moisture meter to monitor and control the drying process, without waiting for the grain temperature to equilibrate, can result in considerable energy and cost savings, not to mention reducing the risk of over-drying. In addition, the AM 5200 delivers the following benefits:
- Rapid analysis in 10 seconds for a wide range of grains, oilseeds, pulses, beans, lentils, seeds and more for Moisture, Test Weight/Hectoliter Weight, and Temperature.
- Leverages the same trusted UGMA and high frequency technology as approved models found at elevators and inspection agencies.
Easy-to-use and read touch screen built into the instrument, with auto analysis mode for multiple samples analyzed in succession.
- Excellent build quality and materials (heavy metal sheeting and Delrin) to extend the life of the instrument and prevent damage during relocation and use in harsh environments.
- Automated sample strike off ensures consistent measurements and reduces the chance of operator error, while a large measurement cell boosts repeatability and accuracy, allowing for the analysis of a more representative sample.
- 150 MHz radio frequency and a large measurement cell, to achieve superior accuracy over handheld units, while also analyzing a more representative sample, thus reducing the potential for user error.
Sadaka, S., & Rosentrater, K. A. (n.d.). Tips on Examining the Accuracy of On-Farm Grain Moisture Meters. https://www.uaex.uada.edu/publications/pdf/FSA1094.pdf