- What is the difference between water activity and moisture content?
Moisture content is a quantitative measure of water in a given product — what percent of the product by weight is water. Moisture content can be a valuable measure of yield and quality. Water activity measures the energy status of the water in the system. Water activity is most helpful for managing product quality and safety, preventing microbial growth, texture changes, shelf life, and more. For more in-depth information, see the FOOD Knowledge Base.
- What are your previous product lines and their lifespans?
METER instruments and product lines are built to last and designed to provide enduring value for customers. We offer support for our products for as long as possible. Our first major product line, introduced in 1988, was supported for nearly 20 years. Our second major product line, introduced in 1999, was also supported for nearly 20 years.
- What is the difference between calibration and verification?
Calibration is performed by METER Group service technicians and certifies that your device is performing within specifications and meets auditing requirements. Verification involves the regular running of the standards by the end user to check instrument performance. The linear offset done through the calibration menu setting does not satisfy the requirements of a full factory recalibration.
- Is annual preventative maintenance required on METER products?
Annual preventative maintenance is highly recommended for all of our instruments. If you require a current calibration certificate on file, METER annual service or maintenance plans can satisfy those requirements. Our service plan option covers preventative maintenance, parts, labor and calibration and extends the warranty of your instrument an additional year, provided the maintenance schedule is maintained.
- Is temperature control important when measuring water activity?
Yes. Water activity is temperature dependent. Temperature effects water activity due to changes in water binding, dissociation of water, solubility of solutes in water, or the state of the matrix. The effect of temperature on the water activity of a food is product-specific.
There’s no good way to predict which types of products are sensitive to temperature, but reading a product at a series of different temperatures will show which products are sensitive. Meat products tend to be fairly stable, however some powdered compounds and sugars are more affected by temperature changes.
- Can your instruments be used to test powders, liquids and solids?
METER instruments can be used to test all types of material. Liquids, solids, gels, and powders are all acceptable.
- How do one minute moisture content measurements work?
METER Group's AQUALAB 3 delivers one minute moisture content readings without the long drying times or other weaknesses of most moisture balances. It does so through a proprietary predictive AI and machine learning system.
- How is a Dynamic Vapor Sorption (DVS) isotherm different from a Dynamic Dewpoint Isotherm (DDI)?
Dynamic Vapor Sorption Isotherms are an improvement upon desiccator-based isotherms. A sample is held in a closed chamber at different humidities until equilibrium. Cycling through environments and collecting data points is automated. DVS isotherms typically include 5-10 data points.
A Dynamic Dewpoint Isotherm is produced with METER-patented technology. It involves continuously pulsing desiccated or humidified air over a sample while near-continuously measuring water activity and moisture content. The Dynamic Dewpoint method offers high resolution data, producing isotherms with hundreds of data points – enough to pinpoint glass transitions.