ZiQi WDH-1S Halogen Moisture Analyzer

Overview

The ZiQi WDH-1S Halogen Moisture Analyzer is a precision thermogravimetric instrument engineered for rapid, reliable determination of moisture content in solid and semi-solid samples via halogen lamp-assisted drying. Unlike conventional oven-drying methods standardized in ASTM D4442, ISO 4687-1, or USP <921>, the WDH-1S applies controlled radiant heat from a high-intensity halogen lamp—optimized for uniform energy distribution across the sample surface and enhanced thermal penetration. This method accelerates evaporation of free (non-bound) water while minimizing thermal degradation of heat-sensitive matrices. The system operates on the principle of mass loss monitoring: real-time weight data is acquired at sub-milligram resolution (1 mg) using a high-stability electromagnetic force restoration sensor, synchronized with precise temperature feedback from an integrated PT-100 probe. The resulting moisture value (%) is calculated automatically as (initial mass − final dry mass) / initial mass × 100, with full traceability to initial tare and endpoint criteria.

Key Features

• Halogen heating module delivering rapid, repeatable thermal profiles—typical drying cycles completed in 3–8 minutes depending on sample type and moisture load
• Electromagnetic force compensation weighing mechanism with 110 g capacity and 1 mg readability, housed in a die-cast aluminum enclosure for mechanical stability and thermal inertia control
• Adjustable temperature range from 40 °C to 199 °C in 1 °C increments, enabling method optimization for diverse materials—from delicate herbs to hygroscopic polymers
• Backlit LCD display showing concurrent readouts: moisture %, dry residue %, elapsed time, current temperature, and real-time mass curve
• 15 programmable drying methods stored onboard—each configurable with target temperature, stop mode (auto, time-based, or slope-based), and endpoint sensitivity
• RS232 serial interface compliant with standard laboratory data capture protocols; supports direct export to LIMS, Excel, or validated reporting software
• Ring-shaped halogen emitter geometry ensuring radial thermal symmetry and eliminating hot-spot artifacts common in rod-style IR heaters
• Compliance-ready design: supports audit trails when integrated with 21 CFR Part 11–compliant software; meets GLP/GMP documentation requirements for QC labs

Sample Compatibility & Compliance

The WDH-1S accommodates heterogeneous particulates, powders, granules, pastes, and thin-sheet solids with minimal sample preparation—ideal for routine testing in food QA (e.g., flour, dried vegetables, pet food), pharmaceutical excipients (lactose, microcrystalline cellulose), polymer pellets (PA6, PET), agricultural commodities (grains, feed), and industrial chemicals (catalysts, pigments). Its open pan design (Ø90 mm) permits direct placement without crucibles or lids, reducing contamination risk and operator variability. Method validation aligns with AOAC 955.04 (moisture in feeds), ISO 1186 (plastics), and USP <921> for loss-on-drying (LOD) equivalence studies. While not certified to IEC 61000-6-3 or CE for standalone medical use, it conforms to EN 61326-1 for EMC in laboratory environments.

Software & Data Management

The analyzer operates autonomously but interfaces seamlessly with third-party data acquisition tools via ASCII-based RS232 protocol. Each measurement generates a timestamped record containing sample ID, method name, start/end time, initial/final mass, temperature profile, and moisture result—with optional checksum and carriage-return line termination. When deployed in regulated environments, integration with validated PC software enables electronic signature, user access controls, change history logging, and PDF report generation meeting FDA 21 CFR Part 11 requirements. All 15 internal methods are editable via front-panel navigation; no firmware update required for parameter adjustment.

Applications

This instrument serves as a primary LOD tool across R&D, production QC, and regulatory compliance laboratories. Typical use cases include moisture verification in incoming raw materials (e.g., starch moisture ≤12.5% per ISO 664), batch release testing of tablet granules (USP <921>), shelf-life stability studies of dehydrated foods, quality screening of recycled plastics prior to extrusion, and calibration verification of Karl Fischer titrators. Its speed and reproducibility make it especially valuable for high-throughput labs performing >50 tests/day where oven methods would bottleneck workflow.

FAQ

What standards does the WDH-1S comply with for moisture testing?
It supports method equivalence to ASTM D4442, ISO 4687-1, AOAC 955.04, and USP <921> when validated per laboratory SOP.
Can the WDH-1S measure bound water or only free moisture?
It quantifies total volatile loss under defined thermal conditions—primarily free and loosely bound water; strongly bound or crystalline water may require higher temperatures beyond its 199 °C limit.
Is calibration traceable to national standards?
Yes—external calibration using NIST-traceable weights (e.g., 10 g, 50 g, 100 g class M2) and reference temperature probes is recommended quarterly per ISO/IEC 17025 guidelines.
Does it support GLP-compliant data archiving?
When paired with validated software, it provides full audit trail, electronic signatures, and immutable data export—fulfilling core GLP data integrity requirements.
How is endpoint detection determined?
Three modes available: automatic (mass change ≤0.1 mg/min over 60 s), timed (user-defined duration), or slope-based (customizable delta-mass threshold per minute).