OHAUS MB25ZH Halogen Moisture Analyzer
| Brand | OHAUS |
|---|---|
| Origin | USA |
| Model | MB25ZH |
| Heating Source | Halogen Lamp |
| Capacity | 110 g / 99 g (max. sample weight) |
| Readability | 0.01 g / 0.005 g |
| Moisture Readability (>10 g sample) | 0.05% |
| Repeatability (3 g sample) | 0.2% |
| Repeatability (10 g sample) | 0.05% |
| Minimum Sample Mass | 0.5 g |
| Recommended Sample Mass | 3–20 g |
| Pan Diameter | 90 mm |
| Temperature Range | 50–160 °C (in 5 °C increments) |
| Heating Time | 1–60 min (30 s steps), 60–90 min (1 min steps) |
| End Point Detection | Timed & Automatic |
| Display | Backlit LCD showing moisture %, solids %, mass, time, temperature |
| Interface | Bidirectional RS232 |
| Operating Ambient | 10–30 °C |
| Dimensions (W×H×D) | 165 × 127 × 280 mm |
| Net Weight | 2.1 kg |
| Sample Pan Handle | Standard |
Overview
The OHAUS MB25ZH 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 heating and high-stability weighing. It operates on the principle of loss-on-drying (LOD): a pre-weighed sample is heated under controlled thermal conditions; the mass loss due to volatilization—primarily water—is measured in real time by an integrated analytical balance, and moisture content is calculated as a percentage of the initial mass. Designed for routine QC/QA laboratories in food, pharmaceutical, chemical, and agricultural sectors, the MB25ZH delivers consistent performance across diverse matrices while maintaining full compliance with standard test methods including AOAC 952.06, ASTM D4442, ISO 11875, and USP <921>. Its robust mechanical architecture—featuring a thermally isolated load cell and optimized airflow path—minimizes thermal drift during heating, ensuring measurement integrity even during extended drying cycles.
Key Features
- Halogen lamp heating system with precise digital temperature control (50–160 °C in 5 °C increments), enabling rapid and uniform thermal energy transfer for accelerated drying without sample charring.
- Thermally isolated electromagnetic force restoration (EMFR) weighing sensor, decoupled from the heating chamber to eliminate thermal interference and preserve accuracy throughout the entire drying process.
- Backlit monochrome LCD display providing simultaneous readouts of moisture %, solids %, current mass (g), elapsed time (min:s), and chamber temperature (°C).
- Six-button intuitive interface with no nested menus—users configure method parameters (temperature, time, endpoint mode) directly via dedicated keys, reducing training time and operational error.
- Bidirectional RS232 serial interface supporting direct connection to label printers, external PCs, or LIMS systems for automated data logging, report generation, and audit-ready traceability.
- Standard stainless-steel sample pan (90 mm diameter) with ergonomic handle for safe handling of hot samples; compatible with optional glass fiber filters and ceramic crucibles for specialized applications.
Sample Compatibility & Compliance
The MB25ZH accommodates a broad range of sample types—including powders, granules, pastes, tablets, herbs, polymers, and coated materials—with recommended masses between 3 g and 20 g for optimal signal-to-noise ratio and repeatability. Its 0.5 g minimum sample requirement supports analysis of high-value or limited-availability materials. The instrument meets essential regulatory expectations for laboratory instrumentation: it supports GLP/GMP-compliant workflows through configurable user access levels (when paired with OHAUS LoggerPro™ software), timestamped method storage, and full audit trail capability. While not inherently 21 CFR Part 11 compliant out-of-the-box, its RS232 output enables integration with validated third-party data acquisition platforms that provide electronic signature, change control, and secure archiving functions required for FDA-regulated environments.
Software & Data Management
OHAUS LoggerPro™ software (sold separately) extends the MB25ZH’s functionality by enabling PC-based method development, real-time graphing of mass loss curves, statistical analysis of replicate runs, and customizable PDF/CSV report generation. All stored methods—including temperature ramp profiles, endpoint criteria (timed vs. automatic slope detection), and calibration history—are retained in non-volatile memory with time/date stamps. Raw mass-vs.-time datasets can be exported for secondary analysis in Excel or statistical packages. For laboratories operating under strict documentation requirements, LoggerPro supports user-defined electronic signatures and role-based permissions, facilitating alignment with ISO/IEC 17025 clause 7.7 (result reporting) and Annex A.2 (data integrity).
Applications
- Food & Beverage: Determination of moisture in flour, coffee beans, dairy powders, snack foods, and pet food per AOAC Official Method 952.06 and Codex Alimentarius standards.
- Pharmaceuticals: Assay of residual solvents and water content in APIs, excipients, and finished dosage forms in accordance with USP <921> and EP 2.5.12.
- Chemicals & Polymers: Monitoring moisture in catalysts, resins, silica gels, and battery electrode materials where hygroscopicity affects reactivity or shelf life.
- Agriculture & Feed: Rapid field-lab verification of grain, hay, and feedstuff moisture for storage stability and nutritional labeling compliance.
- Research & Education: Teaching thermogravimetric principles, method validation studies, and comparative LOD protocol optimization.
FAQ
What is the difference between halogen and infrared heating in moisture analyzers?
Halogen lamps emit broadband near-infrared radiation (700–2500 nm) with higher power density and faster thermal response than traditional IR emitters. This allows more efficient surface and subsurface heating of heterogeneous samples, reducing total analysis time without compromising reproducibility.
Can the MB25ZH be calibrated for traceable accuracy?
Yes—both internal calibration (using built-in reference weights) and external calibration (with NIST-traceable Class M1 or better weights) are supported. Calibration logs—including date, operator ID, and deviation values—are automatically recorded in instrument memory.
Is the MB25ZH suitable for volatile organic compounds (VOCs) analysis?
No. The MB25ZH quantifies total volatile loss assumed to be water. For selective VOC identification or quantification, gas chromatography (GC) or headspace-GC/MS is required. However, it remains valid for total volatiles assessment when referenced against validated SOPs.
How does the automatic endpoint detection work?
The analyzer continuously monitors mass change rate (mg/min). When the rate falls below a user-defined threshold (e.g., ≤0.1 mg/min for 60 s), the system triggers endpoint and calculates final moisture % based on stabilized mass loss.
Does the MB25ZH support multiple user accounts?
Not natively—the device has a single-user interface. However, LoggerPro™ software provides multi-user login, password protection, and activity logging for full accountability in shared-lab environments.
