A wide array of measurement instruments and technologies exist to test the moisture in grains and seeds. The reason for this variety is that moisture is one of the most important variables to control when growing, harvesting, processing and finally, preparing the grain for consumption.
In addition to the quality of the final product, moisture levels completely predict shelf life, product stability, appearance and, of course, price and profitability. Millions of dollars (probably billions) are gained and lost each year by being able to optimize moisture levels when transacting business and processing the product.
Standard Moisture Testing
Most moisture tests are batch oriented. That means a sample of grain (interchangeable with seeds) is gathered. It is then tested in the moisture meter and the results are reported as a single number. The assumptions made are:
- The moisture within the test sample was homogenous (the same)
- The moisture in the test sample was the same (or at least similar) to the larger batch
Wouldn’t it be nice to quantify the validity of these assumptions?
Single Grain Moisture Testing
A single grain moisture tester does just that. It tests one grain and reports the moisture value. While well and good, a single grain doesn’t tell us much. What we’d like is a multitude of single grain tests and then be able to look at the distribution of the moisture in the various grains tested. Doing this one at a time is sometimes the case but there are instruments that automate the process, freeing test personnel to perform other duties while the moisture testing is being conducted.
Shown below are moisture measurements of two batches of rice. The histograms display the spread of the moisture ranges within the two samples. While both samples have the same “average” moisture value (the value that would be obtained with a traditional moisture tester), it is obvious that these two batches are far from the same. Batch one shows a homogenous batch with a traditional “normalized” distribution of moisture content. Batch two shows a batch where the grains are far from homogenous and looking at the two discrete peaks, it was recommended that the customer look at their process to determine the source of the variation. The customer that had this sample used the analysis to explain the reason for a product processing issue was related to many of the grains being far away from their preferred value.
As you can clearly see from this example, providing a single moisture measurement can provide a false sense of security. Being able to provide a quick, accurate measurement of many single grain tests helps the customer have a better understanding of their product’s quality and consistency.
Who Should Use A Single Grain Analyzer?
Customers that want to optimize their product quality and their bottom line profitability should consider a single grain analyzer to supplement (or replace) their traditional batch systems. One of Kett's clients recently commented, "You can use the average moisture content to buy and sell, but to optimize quality and profitability, the dispersion is the key. A batch of grain with a smaller dispersion indicates consistency, higher quality, and easier processibility".
If your firm is having process issues, or you want a better understanding of your raw material or finished goods consistency, please contact us for additional information or to learn more about the wide variety of specialized instruments we offer for moisture analysis.
Download PQ520 Single Grain Moisture Meter Brochure - English version