What is a moisture analyser?
Moisture analysers are specialist laboratory instruments for determining moisture content in solid or semi-solid materials. They are used to rapidly heat small food samples with built-in halogen lamps which can then be weighed precisely (usually in grams) using a loss-on-drying technique.
In this technique, a sample of material is weighed, heated in an oven for an appropriate period, cooled in the dry atmosphere of a desiccator, and then re-weighed. If the volatile content of the solid is primarily water, the LOD technique gives a good measure of moisture content.
Moisture analysers are sometimes referred to as 'moisture balances' or 'moisture meters'.
The manual laboratory method is relatively slow, so automated moisture analysers have been developed that can reduce the time necessary for a test from a couple hours to just a few minutes. These analysers incorporate an electronic balance with a sample tray and surrounding heating element. Under microprocessor control the sample can be heated rapidly and a result computed prior to the completion of the process, based on the moisture loss rate, known as a drying curve.
We supply a range of A&D Moisture Balances and the Adam PMB Moisture Analyser. They all contain halogen lamps - Get In Touch if you need replacement lamps.
What are the main components of a moisture analyser?
The main components of a moisture balance are the sample pan cradle, display interface, heating element and load cell.
When it comes to sample pan types the most common type are aluminium pans which are lightweight and disposable, conducting even heat throughout the drying process. There are also stainless steel pans which are durable and reusable; these are easy to clean but slower to conduct heat compared to aluminium. Using a glass fibre pad in addition to an aluminium pan is best for liquid and stickier samples, preventing errors in results from spattering or bubbling in high moisture samples. Lastly, the least common pans are ceramic pans which are heat resistant, needing a high temperature to analyse samples and takes a longer time to process.
In terms of heating types there are three main types of heating units you can find when looking for moisture analysers. Theses are halogen heating - the fastest method of heating and drying; infrared heating which is good for sensitive samples but slower; and lastly microwave heating for high-moisture content.
Which industries use moisture analysers and why?
There are a variety of moisture analyser applications in a variety of industries. A moisture balance can be found in:
1. The food and beverage industry, measuring moisture in meats, dairy, flour, cereal and snacks.
2. Pharmaceutical applications for measuring moisture content in powders and drugs, and also quality control.
3. The cosmetic, chemical and beauty industry for testing cream and oil content moisture levels, as well as quality control.
4. The construction industry where a moisture analyser will be used for testing concrete, bricks, insulation, cement and woods and how moisture affects durability.
5. Environmental waste management to assess soils, sludge, compost, biofuels and human waste.
6. Agriculture for analysing animal feed and hay.
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