OHAUS EXPLORER Precision Microbalance

Overview

The OHAUS EXPLORER Precision Microbalance is an advanced analytical instrument engineered for laboratories requiring trace-level mass determination with metrological rigor. Operating on electromagnetic force compensation (EMFC) principle, it delivers high reproducibility and long-term stability under controlled environmental conditions (10–30 °C, <90% RH non-condensing). Designed to meet stringent regulatory expectations—including USP , ISO/IEC 17025, and ASTM E898—this microbalance achieves 0.01 mg readability across capacities up to 120 g, making it suitable for quantitative analysis in pharmaceutical development, reference standard preparation, catalyst dosing, and nanomaterial characterization. Its robust architecture integrates thermal compensation algorithms and low-drift sensor design to mitigate effects of ambient temperature fluctuations (0.80 ppm/°C), ensuring consistent performance without frequent manual intervention.

Key Features

• AutoCal™ Fully Automatic Internal Calibration: Triggers at user-defined intervals (3–10 h) or upon ±1.5 °C ambient temperature change; utilizes dual internal calibration masses for linearity verification and adjustment.
• Non-Contact Operation Suite: Four proximity sensors enable touchless tare, zero, print, and door activation—reducing mechanical wear and minimizing cross-contamination risk during sterile or hazardous sample handling.
• SmartTouch Interface: 5.7″ VGA color touchscreen running SmarText™ 2.0 firmware offers intuitive icon-based navigation, multi-language support, and customizable home screen layouts.
• Modular Design: Detachable display module allows flexible installation in fume hoods or confined workspaces while maintaining full functionality and real-time data visibility.
• Integrated Electrostatic Neutralization (EX225D/AD & EX225/AD models): Built-in ionizer continuously emits balanced positive/negative ions to dissipate static charge on samples and containers—critical for low-mass powders, polymers, and insulating materials where electrostatic forces may introduce errors exceeding several milligrams.
• Rapid Stabilization: Achieves reading stability in ≤8 seconds for 0.01 mg resolution models, optimizing throughput in high-volume QC workflows.

Sample Compatibility & Compliance

The EXPLORER series accommodates a wide range of sample types—from hygroscopic reference standards and lyophilized biologics to volatile solvents and nanoparticle dispersions—within its 80 mm diameter stainless-steel weighing pan. Its draft shield features motorized auto-door actuation with vibration-dampened mechanism, eliminating operator-induced disturbances during critical measurements. All models comply with GLP and GMP documentation requirements through integrated real-time clock, user-access logging, and configurable permission levels (1 administrator + 5 standard users). When paired with OHAUS LoggerPro™ or third-party LIMS-compatible software, the balance supports full 21 CFR Part 11 compliance—including electronic signatures, audit trails, and immutable data export (TXT, CSV, PDF with SQC charts).

Software & Data Management

Data integrity is reinforced via native USB mass storage support: raw measurements, metadata (operator ID, timestamp, method name), and statistical summaries export directly to FAT32-formatted USB drives without external PCs. The onboard database stores up to 99 preconfigured weighing applications and 10 formulation protocols. Advanced functions include dynamic minimum weight calculation per USP , statistical quality control (SQC) reporting, pipette calibration workflows, and graphical printouts with trend overlays. Optional Ethernet connectivity enables centralized configuration management and remote diagnostics in networked laboratory environments.

Applications

This microbalance serves as a foundational tool in regulated and research-intensive settings: active pharmaceutical ingredient (API) assay validation, certified reference material (CRM) certification, residual solvent quantification by gravimetric loss-on-drying, catalyst loading in heterogeneous catalysis studies, and micro-dosing of specialty chemicals in fine chemical synthesis. Its precision supports compendial methods requiring ≤0.1% uncertainty—particularly where traditional analytical balances fall short due to insufficient resolution or inadequate repeatability at sub-10 mg loads.

FAQ

What is the minimum weight this balance can reliably measure?
Per USP guidelines (k = 2, u = 0.10%), the typical minimum weight is 20 mg; optimized operation yields a validated minimum of 9 mg under controlled conditions.
Does the balance support GLP-compliant record keeping?
Yes—built-in real-time clock, user authentication, and audit-ready data export formats satisfy core GLP documentation requirements; 21 CFR Part 11 compliance requires optional software licensing and system validation.
How does AutoCal™ differ from standard internal calibration?
AutoCal™ adds environmental intelligence: it monitors both time elapsed and temperature delta simultaneously, initiating calibration only when either threshold is exceeded—reducing unnecessary cycles while maintaining traceability.
Can I connect this balance to a lab network?
Standard configuration includes RS232 and dual USB ports; optional Ethernet interface enables TCP/IP communication for integration into enterprise LIMS or ELN platforms.
Is static elimination available on all EXPLORER models?
Electrostatic neutralization is factory-installed only on /AD-suffixed variants (e.g., EX225D/AD, EX225/AD); non-/AD models require external ionizers for equivalent functionality.