OHAUS Explorer Plus Precision Microbalance EXP Series

Overview

The OHAUS Explorer Plus Precision Microbalance EXP Series is an ultra-micro analytical balance engineered for high-accuracy mass measurement in regulated and research-intensive environments. Utilizing electromagnetic force restoration (EMFR) technology with dual non-contact position sensors, the EXP125DZH/AD achieves stable, drift-compensated weighing performance at sub-10 µg readability levels. Its design addresses critical requirements in pharmaceutical QC labs, material science R&D, reference standard preparation, and metrology traceability workflows—where measurement uncertainty, repeatability, and data integrity are governed by ISO/IEC 17025, USP , and ASTM E898 standards. The balance integrates a fully automatic internal calibration system with temperature-triggered recalibration, ensuring continuous compliance without manual intervention. With a maximum capacity of 82 g (high-sensitivity mode) or 120 g (standard mode), it delivers optimal resolution across diverse sample mass ranges while maintaining full linearity and thermal stability.

Key Features

• 7-inch detachable TFT color touchscreen with 16.7 million colors and chemically strengthened glass panel—optimized for gloved operation and glare-free viewing under laboratory lighting.
• Automatic leveling system with real-time tilt detection and motorized adjustment—eliminates manual bubble-level dependency and ensures consistent sensor alignment.
• Enhanced draft shield with auto-sensing anti-pinch doors, electrostatic-dissipative glass, and integrated ionizer (ION-100A optional)—reduces electrostatic interference and environmental perturbation during low-mass measurements.
• Modular metal chassis with zinc-alloy weighing pan—provides mechanical rigidity, corrosion resistance, and long-term dimensional stability under repeated thermal cycling.
• Time-synchronized NTP client support and HID-compliant USB interface—enables seamless integration into networked lab systems without driver installation and supports synchronized timestamping for audit-ready records.
• Comprehensive user management: 4+1 role-based access levels (Admin, Supervisor, Operator, Guest + System Default) with encrypted password policies and 100,000-entry internal system log storage.

Sample Compatibility & Compliance

The EXP125DZH/AD accommodates samples ranging from 2 mg (minimum weight per USP 0.1% tolerance) to 120 g, supporting applications including reference standard dispensing, catalyst loading, nanoparticle mass quantification, and micro-vial filling verification. Its sealed sensor chamber and anti-static architecture minimize drift caused by humidity gradients or triboelectric charging. The balance meets CPA certification requirements in China and is configured to comply with international regulatory expectations—including ISO 9001 quality management, ISO/IEC 17025 testing laboratory competence, and GLP/GMP documentation protocols. Built-in audit trail functionality logs all critical events (e.g., calibration, tare, user login/logout, parameter changes) with immutable timestamps, satisfying FDA 21 CFR Part 11 electronic record requirements when paired with validated software.

Software & Data Management

• Internal memory stores up to 3,000 sample IDs with customizable metadata fields (e.g., batch ID, analyst name, expiry date).
• Direct USB export of CSV-formatted weighing records—including raw values, timestamps, operator IDs, and environmental conditions—to external drives or LIMS-compatible systems.
• Ethernet TCP/IP connectivity enables remote configuration via web browser and integration with enterprise lab informatics platforms using standard HTTP/HTTPS APIs.
• Optional fingerprint scanner (FIN-100A) and wireless module (LM842) provide biometric authentication and mobile data transfer capabilities for decentralized workflows.
• Support for third-party instrument control via RS232 or USB-to-serial adapters—compatible with common automation frameworks including LabVIEW, Python PySerial, and MATLAB Instrument Control Toolbox.

Applications

The Explorer Plus EXP Series serves as a foundational metrology tool across multiple disciplines: quantitative formulation of active pharmaceutical ingredients (APIs) under ICH Q5C guidelines; density determination of high-value materials using sinker-based hydrostatic methods (accessory kit AV EP VP PA); pipette calibration per ISO 8655 with automated volume calculation and pass/fail reporting; statistical quality control (SQC) with built-in tolerance banding and histogram generation; and container content uniformity testing per USP . Its peak-hold function supports transient mass monitoring during solvent evaporation or gas absorption experiments, while the differential weighing mode enables precise loss-on-drying (LOD) and ash content analysis. In academic settings, it facilitates gravimetric synthesis validation, nanomaterial yield assessment, and isotopic tracer quantification where trace-level accuracy is non-negotiable.

FAQ

What is the minimum weight that complies with USP requirements?
20 mg (at 0.1% tolerance level), verified using certified test weights traceable to NIST or equivalent national metrology institutes.

Does the balance support 21 CFR Part 11-compliant electronic signatures?
Yes—when used with validated software and enabled audit trail settings, it provides secure user authentication, immutable event logging, and electronic record retention per FDA requirements.

Can the EXP125DZH/AD be integrated into a centralized lab data management system?
Yes—via Ethernet TCP/IP, USB host export, or optional Wi-Fi/Bluetooth modules, enabling direct ingestion into LIMS, ELN, or MES platforms using standard file formats and RESTful APIs.

Is external calibration required after internal calibration?
No—fully automatic internal calibration eliminates routine external checks; however, periodic verification using accredited reference weights is recommended per ISO/IEC 17025 clause 6.5.2.

What environmental conditions affect stabilization time?
Ambient temperature fluctuations >0.5 °C/hour, air currents exceeding 0.2 m/s near the draft shield, or static charge buildup on samples may extend stabilization beyond the typical 5-second specification.