How a moisture analyser works: an insight into precise moisture measurement and its application

Have you ever wondered how it is possible to accurately determine the water content in materials? Moisture analysers provide the answer to this question. Delve into the world of precise measurement technology and discover the many possible applications of these devices.

What is a moisture analyser?

A moisture analyser is a specialised piece of laboratory equipment designed to measure the percentage of water in materials. This technology is used in industries such as food, pharmaceutical and agriculture, where accurate moisture determination is crucial for quality assurance, consistency and product integrity.

1. Basic principle: The moisture analyser measures the loss of water in a sample by heating and monitoring the change in weight. This allows the water content to be calculated accurately.
2. Significance: Controlling moisture ensures that products such as food, pharmaceuticals and chemical materials retain their optimum consistency, shelf life and stability.

How does a moisture analyser work?

The Gram FM series uses the thermogravimetric method to determine moisture. This method relies on the instrument to heat the sample in a controlled manner and to measure the weight continuously to accurately account for the loss of moisture. Key components include:

Halogen heater:

Our Gram FM series is equipped with halogen heaters that provide even and controlled heating of the sample, which supports rapid evaporation of moisture and precise analysis.

Three heating modes

• Standard heating: In this mode, the sample is heated evenly and in a controlled manner. The temperature rises continuously and remains at the desired level, ensuring precise and stable drying. This mode is ideal for samples that require constant heating.
• Step-by-step heating: This mode heats the sample in several timed steps. Only the timer is used to adjust the heating at specific intervals. The step-by-step temperature build-up is particularly suitable for sensitive samples that require gentle drying.
• Rapid heating: In this mode, the sample is quickly heated to the desired temperature. Rapid heating enables time-saving drying and is ideal for applications where rapid moisture determination is required without damaging the sample.
• Slow heating: In this mode, the temperature of the sample is increased with a lower heating power. This gentle approach prevents moisture from evaporating too quickly, which dries the sample evenly and minimises the risk of sample changes, such as deformation or burning. The mode is particularly suitable for sensitive or heterogeneous samples that require gentle heating to achieve accurate and stable results.

The thermogravimetric method in a moisture analyzer

The thermogravimetric method in a moisture analyzer measures moisture content by recording the weight loss of a sample as it’s heated over time. This method works by placing the sample in the moisture analyzer’s pan, where it is subjected to controlled heating. As the temperature rises, moisture in the sample evaporates, causing a reduction in weight. The analyzer tracks this weight change continuously until a constant weight is achieved, indicating that all moisture has been removed. The final weight loss, relative to the initial weight, is calculated to determine the moisture content of the sample accurately.

Applications of Moisture Analyzers

Moisture analyzers serve multiple industries, from quality control in food and beverage to ensuring correct formulation in pharmaceuticals and cosmetics. Key applications include:

The Gram FM: Our moisture analyzer for your Lab

The Gram FM moisture analyzers are specialized devices for precise moisture measurement in sample materials, which are particularly used in laboratory and industrial environments. It uses the thermogravimetric process: the controlled heating of the sample using a halogen lamp accelerates the evaporation of moisture. The analyzer measures weight loss in real time to reliably determine moisture content.

The FM series offers a range of features that enable flexible and customizable moisture analysis. There are four different drying programs to choose from – time-based, temperature-controlled, automated and step-by-step – which allow the drying process to be optimally tailored to the respective sample. In addition, up to 20 individual drying profiles can be saved, increasing efficiency during repeated measurements.

With a user-friendly, multifunctional display, the analyzer shows all relevant process data, including drying progress and moisture content. The FM models also have an RS-232C interface, which enables easy data transfer to a PC or printer and creates GLP-compliant reports to meet the high documentation requirements in laboratories. The analyzers are compact, have non-slip feet for safe placement and are available in both 120g and 310g capacities with variable temperature ranges from 60°C to 160°C.

The Gram RH: Advancement in humidity calculation

The Gram RH moisture analyzers are highly-developed instruments for accurate moisture determination, ideal for demanding laboratory and industrial applications. They use the thermogravimetric process and accelerate drying using halogen lamps to determine the moisture content based on the change in weight.

The RH series offers four drying programs (fast, slow, step and standard), allowing the drying process to be adapted to different sample types. The analyzers have a USB interface for direct export of data to spreadsheets and allow the connection of a PS/2 keyboard for easy data entry. Up to 20 drying methods can be saved, which is particularly helpful for frequent repetitions.

The alphanumeric display shows real-time data and graphics of the moistening process, allowing users to easily monitor drying progress. In addition, the RH models are equipped with GLP-compliant logging, which ensures standardized reports. They are available in variants with a capacity of 110 g or 210 g and offer very high measurement accuracy with a resolution of up to 0.01% for larger sample quantities.

Ready to improve precision in your lab?

Discover how Gram’s moisture analyzers can make your processes faster, more accurate and fully traceable. Contact our team to request a personalised quote or technical guidance — and experience the difference precise moisture measurement can make in your production or laboratory workflow.