How Does a Halogen Moisture Analyzer Work?

What Is a Halogen Moisture Analyzer?

A halogen moisture analyzer is a laboratory instrument that measures the moisture content of a sample using the loss-on-drying (LOD) method with a halogen heating source. It combines a high-precision balance with a halogen lamp that quickly heats the sample while continuously recording weight changes until stable.

Typical models, such as the KHT-M18 series, are widely used in food, pharmaceutical, chemical, and agricultural industries for quality control and production monitoring.

How Does a Halogen Moisture Analyzer Work?

The instrument measures moisture content by comparing the weight of a sample before and after controlled heating.

Step-by-step process:

1. Initial weighing – Place the sample on the pan, tare, and record the weight.

2. Halogen heating – The lamp rapidly heats the sample to the set temperature (40–160°C or up to 199°C depending on the model).

3. Moisture evaporation – Water in the sample evaporates, and the balance continuously tracks weight loss.

4. Stable endpoint – Once weight change falls below the threshold or time expires, the test stops.

5. Result calculation – Moisture content is automatically displayed as a percentage.

Why Is Halogen Heating Used?

Halogen heating provides fast, stable, and uniform heat, making it more efficient than traditional drying ovens.

• Faster results – Analysis completes in minutes instead of hours.

• Uniform drying – Radiant halogen heat minimizes temperature gradients.

• Energy efficiency – Compact heating design reduces power use.

• Better control – Adjustable modes:

• Standard mode: balanced heating, suitable for most samples.

• Fast mode: rapid heating for high-moisture samples.

• Soft mode: gentle ramping to avoid scorching heat-sensitive samples.

Operating Modes and Stop Criteria

Halogen analyzers allow flexible stop conditions:

• Automatic stop – Ends when weight change is below a set threshold.

• Manual stop – Operator manually ends the test.

• Timed stop – Runs for a pre-set duration (1–99 minutes).

This flexibility ensures reliable results for different materials, from powders and seeds to pharmaceutical tablets.

Key Specifications of KHT-M18 Series

Best Practices for Accurate Measurements

To achieve consistent and reliable results, follow these tips:

• Warm up the instrument for 30 minutes before testing.

• Calibrate the balance using a 100 g standard weight regularly.

• Select the appropriate heating mode based on sample type.

• Ensure samples weigh at least 1–3 g for reliable accuracy.

• Avoid testing flammable, explosive, toxic, or corrosive substances.

• Clean the weighing pan and ensure proper ventilation.

Calibration Procedure

Calibration ensures accuracy of both balance and heating.

1. Place a 100 g standard weight on the pan when prompted.

2. Confirm display matches the reference weight.

3. For multi-point calibration, repeat with 50 g and 20 g weights.

4. For temperature calibration, use a probe and adjust settings if deviation is detected.

Typical Applications

• Food & Agriculture: grain, flour, dairy powders, seeds.

• Pharmaceuticals: raw materials, powders, and tablets.

• Chemicals & Plastics: polymers, resins, and hygroscopic chemicals.

• Cosmetics: creams and powders requiring moisture consistency.

Frequently Asked Questions (FAQ)

**Q1: What principle does a halogen moisture analyzer use?**

A: It works on the loss-on-drying principle, heating the sample with a halogen lamp while monitoring weight loss to calculate moisture content.

**Q2: How fast is halogen heating compared to oven drying?**

A: Halogen analyzers provide results within minutes, while traditional oven drying may take several hours.

**Q3: Can all materials be tested?**

A: No. Flammable, explosive, toxic, or corrosive samples should not be tested, as heating may release dangerous gases or cause hazards.

**Q4: How often should calibration be performed?**

A: Balance calibration should be done daily or weekly, while temperature calibration is recommended monthly or when precision is critical.

**Q5: What is the minimum sample weight required?**

A: At least 1 g is recommended; typically 3–5 g ensures stable and reliable results.

Conclusion

Halogen moisture analyzers, such as the KHT-M18 series, combine rapid halogen heating with precision weighing to deliver fast and reliable moisture analysis. With proper calibration, correct mode selection, and adherence to safety practices, they are indispensable tools in food, pharmaceutical, and chemical industries.