Microwave Moisture Analyzer

What is the Microwave Moisture Analyzer?

A microwave moisture analyzer heats the sample by microwave energy that couples directly with water molecules, drying large or high-moisture samples evenly and quickly. It suits meat, dairy, cheese, pastes and bulky products where surface heating is slow.

Overview

Microwaves at 2.45 GHz heat water throughout the sample volume rather than only at its surface, so large or wet samples dry quickly and evenly. Sample sizes of 5 to 100 g are dried in about 2 to 6 minutes, and power is regulated from a few watts to 900 W to prevent scorching. A built-in balance weighs continuously, with typical readability of 1 to 10 mg. Because microwaves couple to water, dry regions heat little, so results are less affected by sample surface and thickness. A fiberglass pad or sample container transparent to microwaves holds the sample. Safety shielding and interlocks are required, and the instrument suits meat, dairy, tomato paste and similar products where oven drying takes many hours. Not suitable for samples with metal content.

How does it work?

A moisture balance applies the thermogravimetric loss-on-drying principle. The sample, typically 0.5 to 20 g, is placed on a pan inside a heating chamber, and its initial mass is recorded. A heater, such as a halogen lamp, infrared emitter, metal tube or microwave source, raises the sample temperature to a set value, commonly 40 to 200 C. A built-in weighing cell records mass continuously as water and other volatiles evaporate. The analysis ends when mass change falls below a defined rate, for example 1 mg per 50 seconds, or after a set time. Moisture content is calculated as mass loss divided by initial mass. Temperature sensors and profiles, such as standard, rapid or stepwise heating, control energy input to avoid decomposition of the sample.

What are the key features?

• 2.45 GHz microwave heating throughout the sample volume
• Adjustable power from a few watts to 900 W to prevent scorching
• Fast drying of 5 to 100 g samples in about 2 to 6 minutes
• Microwave-transparent sample pads or containers
• Safety shielding with door interlock and leakage monitoring

What are the technical specifications?

A typical microwave moisture analyzer configuration offers readability of 1–10 mg, sample mass range of 5–100 g, microwave frequency of 2.45 GHz, microwave power of Adjustable to 900 W, moisture readability of 0.01–0.1% and typical analysis time of ≈ 2–6 min. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Microwave Moisture Analyzer is used in meat and fish moisture, dairy and cheese, tomato paste and sauces and bulky or high-moisture samples. Across the wider Moisture Balances class, laboratories also deploy it for food and grain moisture testing, pharmaceutical loss on drying and plastic granule moisture control.

Which standards and certifications apply?

Relevant standards and methods include USP <731>, Ph. Eur. 2.2.32, ISO 712, ISO 6540, AOAC 925.10, ASTM D6980 and GB 5009.3. Certification candidates for this model are CE, Microwave leakage safety test and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Install the instrument on a level, vibration-free bench, away from drafts and direct heat, since air movement affects the weighing cell. Allow warm-up before use and calibrate the balance with certified weights. Verify temperature with a calibrated temperature kit, because heater drift changes results. Keep the chamber, reflector and pan clean, as residues absorb heat and alter drying. Use consistent sample mass and distribution, for example a thin even layer, to ensure reproducibility. Hazardous or flammable volatile samples can be unsafe in a heated chamber, so assess each method. Document method parameters, and validate against a reference method when compliance is needed.

How do I select the right Microwave Moisture Analyzer?

Select the microwave analyzer for wet, bulky or poorly conducting samples that halogen or infrared heating dries slowly. It is costlier and unsuitable for metal-containing samples. In the RFQ, specify sample types, mass range, power, readability and safety certification.

How does it compare with other Moisture Balances variants?

Choose the heating technology by sample type. Halogen and infrared units suit most solids and powders, tubular heaters give gentler and more uniform heating for sugars and polymers, and microwave units penetrate large or high-moisture samples quickly. Then check readability, with 1 mg for routine work and 0.1 mg for low-moisture samples or small masses. Consider capacity, usually 50 to 200 g, and temperature range. Validate the method against a reference such as oven drying or Karl Fischer titration, since loss-on-drying also captures other volatiles. Look at programmable drying profiles, data outputs and audit trail for regulated use. Also check sample pans, pan handlers and ease of cleaning, which influence throughput and reproducibility.