Tubular Metal-Heater Moisture Analyzer

What is the Tubular Metal-Heater Moisture Analyzer?

A tubular metal-heater moisture analyzer heats the sample with a ring-shaped metal or ceramic heating element around the pan, giving uniform heating and stable temperature. It suits sugars, polymers, cheese and other materials that scorch under intense radiation.

Overview

In this design a ring or tubular heating element surrounds the sample and emits infrared heat at lower intensity than a halogen lamp, with gentle and uniform warming over the sample surface. The heater has high thermal mass, which stabilizes temperature and reduces overshoot, so results are very reproducible, although time to temperature is longer at 3 to 5 minutes. Readability is 1 mg, with 0.1 mg versions for low-moisture samples, and capacity up to 120 g. Metal heaters last for many years with no consumable lamp, reducing maintenance. Typical drying temperature is up to 200 C. The design is suitable for polymers, sugar-rich products, dairy and organic materials that would caramelize or burn under strong halogen radiation.

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?

• Ring or tubular metal heating element with gentle uniform heat
• High thermal mass for stable temperature with low overshoot
• No consumable lamp, reducing maintenance cost
• Suited to sugar, dairy, polymer and organic samples
• Readability of 1 mg with 0.1 mg option for low moisture

What are the technical specifications?

A typical tubular metal-heater moisture analyzer configuration offers readability of 1 mg (0.1 mg optional), sample capacity of 50–120 g, moisture readability of 0.01–0.1%, temperature range of 40–200 C, heating source of Ring or tubular metal heater and time to 105 C of ≈ 3–5 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 Tubular Metal-Heater Moisture Analyzer is used in sugar and confectionery moisture, dairy and cheese testing, polymer and resin moisture and organic powders that scorch easily. 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, ISO 9001 manufacturing and RoHS; 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 Tubular Metal-Heater Moisture Analyzer?

Select the tubular heater when samples scorch under halogen radiation or when long-term stability and low maintenance matter more than speed. It warms more slowly than halogen. In the RFQ, specify readability, capacity, temperature range and sample type.

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.