Moisture analysers: how can moisture content be determined quickly?

The moisture analysers — also known as thermobalances — combine a precision weighing cell and halogen/IR heating to quantify moisture by loss on drying (LOD). In just a few minutes, they deliver repeatable results in % moisture or % dry matter, with GLP/GMP traceability. From goods-in QC to in-process control, they secure batch release in food, pharma, chemical and environmental labs while cutting turnaround times versus a drying oven. Temperature range 40–230 °C, resolutions down to 0.1 mg and LIMS connectivity complete the package.

What are the different types of loss-on-drying moisture analysers?

At the heart of a moisture analyser is an integrated balance (readability 1 mg to 0.1 mg) coupled to a heating module (up to ~230 °C). The principle: measure the mass loss of a sample during drying, then calculate % moisture or % dry matter. Three main technologies:
• Halogen/ceramic IR: the laboratory standard. Fast heat-up, uniform heating, analysis times of 2 to 10 minutes depending on the matrix.
• Microwave: ideal for very wet samples (pastes, sludges). Volumetric drying, shorter cycles, less suited to fine powders.

Key functions: gentle/standard/fast/step profiles, endpoint detection by rate of change, method libraries, temperature and balance calibration, user management, audit trail (21 CFR Part 11 optional), USB/Ethernet interfaces for LIMS. Accessories (pans, glass fibre filters for liquid/fatty samples, calibration kits) are critical for repeatability.

In which sectors and applications is a moisture analyser used?

• Food & nutraceuticals: cereals (correlation to ISO 712), dairy, meat, coffee/cocoa; control of drying processes, rapid batch release.
• Pharmaceutical & biotech: powders, granules, capsules, excipients; in-process control, compliance with Ph. Eur./USP, reduced waiting times versus oven-drying.
• Cosmetics: creams, pressed powders; stability and texture, formulation optimisation.
• Chemicals & plastics: resins, granules, additives; moisture control prior to extrusion/moulding to prevent defects.
• Environment: sludge, soils; laboratory indicators for drying and dry-matter content.
• R&D and quality control: correlation with reference methods, development of specific methods, LIMS/ERP traceability.
Cross-cutting benefits: fast results, lower energy use and reagent-free (vs Karl Fischer), high ergonomics and repeatability.

The various types of moisture analysers available

Frequently asked questions about loss-on-drying (LOD) moisture analysers

What’s the difference between halogen and ceramic IR?
Both heat by radiation. Halogen ramps up faster; ceramic is more rugged. Choose based on required throughput and robustness.

How can I prevent sugars from charring?
Use a gentle or step profile, lower the maximum temperature, add a glass fibre filter, and limit the sample load.

Do I need to calibrate the instrument?
Yes: calibrate the balance (calibration weights) and verify the temperature (probe/kit). Schedule periodic GLP-traceable checks.

What about volatile or flammable solvents?
Avoid flammable samples. If volatile, work at low temperature, in a fume cupboard, with small loads, and follow the manufacturer’s safety guidance.

How does accuracy compare with an ISO/AOAC oven?
Very good once the method is correlated. Validate a product/reference curve and lock the parameters for routine use.

Is 21 CFR Part 11 compliance available?
On selected models: user management, audit trail, electronic signatures, and secure export to LIMS/ERP.

What maintenance is required?
Regular cleaning of the chamber, periodic replacement of the lamp/IR emitter when worn, calibration checks, and firmware updates.