OHAUS MB35 Halogen Moisture Analyzer

Overview

The OHAUS MB35 Halogen Moisture Analyzer is a precision laboratory instrument engineered for rapid, reliable quantification of moisture content in solid and semi-solid samples using the loss-on-drying (LOD) principle. It employs a high-intensity halogen lamp as its heating source—delivering uniform thermal distribution across the sample surface and enabling faster, more reproducible drying cycles compared to traditional infrared or convection-based systems. The analyzer operates by continuously monitoring sample mass loss during controlled thermal treatment, calculating moisture percentage based on initial and final dry weights. Its dual readability mode (0.001 g absolute mass and 0.01% relative moisture resolution) supports applications requiring trace-level sensitivity in quality control, raw material verification, and regulatory testing workflows. Designed for routine use in pharmaceutical QC labs, food processing facilities, polymer manufacturing, and academic research environments, the MB35 integrates robust mechanical architecture with thermally stable weighing mechanics to minimize drift and ensure measurement integrity over extended operational periods.

Key Features

• Halogen heating system with programmable temperature range from 50 °C to 160 °C in 5 °C increments—optimized for thermal stability and minimal sample degradation
• High-resolution dual-display capability: simultaneous readout of moisture %, elapsed time, current temperature, and real-time mass (g)
• Backlit monochrome LCD (128 × 64 pixel matrix) with intuitive icon-driven navigation and ergonomic keypad layout for glove-compatible operation
• Configurable endpoint detection: timer-based, auto-stop (mass-change threshold), or manual termination—enabling method flexibility across diverse matrices
• GLP-compliant data logging and reporting via integrated RS232 serial interface; supports direct connection to label printers, PCs, and LIMS systems
• Stainless steel weighing pan (9 cm diameter) mounted on a draft shield-compatible platform; unit housed in durable ABS enclosure with ventilation-controlled thermal management

Sample Compatibility & Compliance

The MB35 accommodates a broad spectrum of non-volatile and low-volatility materials, including powders (e.g., APIs, excipients, flour), granules (catalysts, fertilizers), pastes (adhesives, slurries), and thin-film solids (coatings, films). It is not intended for highly volatile solvents, reactive hygroscopic compounds, or samples prone to sublimation above 160 °C. All firmware and calibration routines adhere to Good Laboratory Practice (GLP) requirements, with timestamped, operator-ID-tagged printouts supporting audit readiness. While the instrument itself does not carry FDA 21 CFR Part 11 certification, its RS232 output enables integration with validated third-party software platforms compliant with 21 CFR Part 11, ISO/IEC 17025, and USP guidelines for moisture determination.

Software & Data Management

Data export is performed via ASCII-formatted RS232 transmission at standard baud rates (9600 bps default), compatible with terminal emulators, spreadsheet applications, and custom LIMS interfaces. Printouts include sample ID, start/end times, set temperature, total drying duration, initial/final mass, moisture %, and repeatability indicators. Internal memory retains no measurement history—ensuring data sovereignty and simplifying compliance validation. Optional OHAUS AC-300 software (sold separately) provides method library storage, statistical analysis (mean, SD, RSD), trend charting, and PDF report generation with digital signature fields for electronic record retention.

Applications

• Pharmaceutical: Verification of residual solvent levels in lyophilized products per ICH Q5C; moisture specification checks for tablet granulations (USP )
• Food & Agriculture: Determination of water activity proxies in cereals, dairy powders, and pet food; shelf-life modeling input
• Chemicals & Polymers: Monitoring hygroscopicity of silica gels, zeolites, and engineering resins prior to extrusion or molding
• Academic Research: Method development for LOD-based moisture profiling in novel biomaterials and nanocomposites
• Quality Assurance: In-process checks for consistency across batch production lines where moisture directly impacts flowability, compressibility, or stability

FAQ

What standards does the MB35 comply with for moisture analysis?
The MB35 conforms to ASTM D4442 (wood moisture), ISO 712 (cereals), and AOAC 952.08 (foodstuffs) methodologies when operated under validated SOPs. Its hardware design supports alignment with USP , though full pharmacopeial compliance requires user-established method validation.
Can the MB35 be calibrated with traceable standards?
Yes—internal calibration uses OHAUS-certified weight sets (e.g., 10 g Class M2); external verification may be performed with NIST-traceable reference standards such as sodium tartrate dihydrate (15.66% nominal moisture) or calcium carbide reaction standards.
Is the halogen lamp replaceable by the end user?
The halogen heating module is a field-replaceable unit (FRU); replacement requires no recalibration but must be performed by trained personnel using OHAUS-specified lamps (P/N MB35-LAMP) to maintain thermal profile fidelity.
Does the MB35 support multiple user accounts or password protection?
No—the device lacks multi-user authentication. Access control and audit trails are implemented externally via connected PC software or LIMS integration.
What maintenance is required for long-term accuracy?
Routine cleaning of the pan and chamber with lint-free isopropyl alcohol wipes; annual verification of temperature uniformity (using calibrated PT100 probe arrays) and mass repeatability per ISO 17025 internal audit protocols.