Moisture analyzers are precision instruments providing documentable data on moisture content, or the percentage of moisture in a product.
Examples of incorrect moisture content include soggy potato chips and sugar that lumps up in the bowl, and dried out cookies.
While these examples result from moisture in the atmosphere affecting product quality, moisture content is highly critical when manufacturing and processing a seemingly endless variety of products.
It is in the manufacturing of products that moisture content standards apply. In the sugar example cited above, moisture content according to the EU sugar policy may be a maximum of 0.06%
Moisture content standards apply to virtually any product but first you should understand that there are different types of moisture. It can be found on the surface, in pores or capillaries, and chemically bonded.
How to Measure Moisture Content
Moisture content can be measured three ways: chemical, spectroscopic and thermogravimetric, all described in the link above.
An example of the thermogravimetric method is a tabletop moisture analyzer. These units complete the task in minutes using samples weighed in grams. Heat is applied by halogen or infrared heaters mounted on a precision balance.
Practical Applications for Moisture Analyzers
Moisture content recommended by government and industry standards applies to a broad spectrum of consumer and industrial products. Here are examples.
Testing Moisture in Powdered Milk
The Canadian Dairy Commission targets moisture content for powdered milk at 3- 4% stating that low moisture content does not affect nutritive value after years of storage.
A method to confirm that powdered milk meets standards can include employing the IL-50-001 moisture analyzer available from Tovatech as a quality control procedure after spray drying and prior to packaging.
Measuring Wood Pellet Moisture Content
ASTM E-871 is the guide for moisture content cited in the Pellet Fuel Institute standard for finished pellets. For premium pellets the standard is ≤ 8% (compared to cordwood at 20% to 60%).
Final pellet moisture content can be confirmed prior to bagging using a moisture analyzer such as the Torbal ATS 60 available from Tovatech.
Moisture in Grain and Flour
A University of Minnesota Extension Report states that wheat and barley grain must have a moisture content of 13% to 14% for safe storage. A study at the Institute of Food Science and Technology, Faisalabad, Pakistan, concluded that flour with moisture content between 9% and 10% is suitable for extended shelf life.
Moisture analyzers such as the IL Series are ideal for small-sample validation of the moisture content of grain and flour.
Checking Moisture Content of Injection Molded Plastics
Moisture content of injection molded plastics is critical to performance. For example, a polymer manufacturer may state that his product has a moisture content of 0.20 percent by weight or 2,000 parts per million.
Periodic checks with a benchtop moisture analyzer for plastic resins provides assurances that moisture content is on target, or otherwise call for pre-processing adjustments.
Moisture Analysis for Concrete Construction
Quality control standards for ingredients used in concrete are specified by standards issued by the ASTM and Canadian Standards Association.
A benchtop moisture analyzer for concrete production helps speed the process by providing accurate feedback to keep in-line moisture measuring equipment running at its best without shutting down the process.
Analyzing Sludge Dewatering
Moisture content is critical to the acceptability of treated sewage sludge as an acceptable product for use as a fuel and a nutrient-rich organic material.
Moisture analyzers, both thermogravimetric and microwave, play vital roles in quality control procedures at sludge dewatering plants.