A&D GH-202 Professional Analytical Balance

Overview

The A&D GH-202 Professional Analytical Balance is an ultra-micro precision weighing instrument engineered for laboratories requiring high reproducibility, traceable calibration, and regulatory compliance in routine analytical and quality control workflows. Based on electromagnetic force compensation (EMFC) transduction technology, the GH-202 delivers dual-range readability—0.1 mg across its primary 220 g capacity and enhanced 0.01 mg resolution within a dedicated 51 g sub-range—enabling accurate quantification of small-mass samples without manual range switching. Its monolithic sensor architecture, combined with active temperature compensation and real-time environmental adaptation algorithms, ensures metrological stability under variable lab conditions. Designed and manufactured in Japan by A&D Co., Ltd.—a globally recognized ISO 9001-certified instrumentation developer—the GH-202 meets stringent international metrological requirements for Class I analytical balances per OIML R 76-1 and conforms to the mechanical and procedural specifications outlined in USP , ASTM E898, and ISO 17025 for accredited testing laboratories.

Key Features

• Internal motorized calibration system with integrated reference weights: single-button initiation triggers full-scale auto-calibration with automatic drift compensation.
• Real-time environmental adaptation: built-in temperature and vibration sensors dynamically adjust damping parameters and sensitivity to maintain repeatability in non-ideal environments (e.g., near HVAC vents or shared benchtops).
• Dual-range weighing mode: seamlessly switches between 220 g @ 0.1 mg and 51 g @ 0.01 mg resolution, optimized for both bulk sample preparation and micro-quantity formulation.
• GLP/GMP-compliant data integrity: stores date/time stamps, operator ID codes, balance serial number, calibration history, and ambient temperature logs with configurable retention policies.
• Below-balance hook assembly: supports density determination, magnetic susceptibility assessment, and buoyancy-corrected measurements using suspended fixtures.
• Auto-power-on functionality: initiates warm-up sequence and zero stabilization automatically upon AC power application—eliminating manual activation delays in high-throughput settings.
• Multi-unit conversion engine: supports 8 standardized mass units (g, mg, oz, ozt, ct, dwt, GN, tl), percent weighing, piece counting, and net/gross/tare arithmetic.

Sample Compatibility & Compliance

The GH-202 accommodates standard laboratory samples—including powders, granules, liquids in tared vessels, and small solid components—within its 90 mm diameter stainless-steel weighing pan and draft shield enclosure. Its compact yet rigid chamber design minimizes air turbulence while permitting easy access for pipette tips, crucibles, and filtration assemblies. All firmware and hardware configurations adhere to Good Laboratory Practice (GLP) and Good Manufacturing Practice (GMP) documentation standards. Audit trails generated via RS-232C output include immutable timestamps, user-defined ID codes, calibration verification records, and system diagnostics—fully compatible with FDA 21 CFR Part 11 electronic record requirements when paired with validated third-party LIMS or ELN platforms. The balance is certified to ISO/IEC 17025:2017 for measurement uncertainty evaluation and supports traceability to NIST-traceable standards through documented internal calibration procedures.

Software & Data Management

The GH-202 interfaces natively with A&D’s WinCT-ROM software suite via RS-232C, enabling bidirectional communication for remote configuration, real-time data streaming, and automated report generation. WinCT-ROM supports customizable data export formats (CSV, TXT, Excel-compatible), batch logging with metadata tagging, and scheduled calibration reminders. When connected to AD-8121B thermal printers or networked PCs, the balance outputs fully compliant GLP reports containing balance ID, calibration status, environmental readings, and operator credentials. All stored data entries are write-protected after acquisition and retain full chronological integrity—no post-hoc editing or deletion is permitted without system-level administrative override, ensuring data provenance for regulatory audits.

Applications

• Pharmaceutical QC: active pharmaceutical ingredient (API) assay, excipient blending verification, and tablet weight uniformity testing per USP .
• Chemical synthesis: stoichiometric reagent dispensing, catalyst loading, and yield calculation in R&D and pilot-scale reactions.
• Materials science: powder density characterization, thin-film mass deposition analysis, and nanomaterial gravimetric dosing.
• Clinical research: preparation of calibrated reference standards for immunoassays and mass spectrometry calibration curves.
• Environmental testing labs: filter weighing for particulate matter (PM2.5/PM10) analysis per EPA Method 201A.
• Academic teaching labs: foundational instruction in metrology, uncertainty propagation, and statistical process control using certified reference materials.

FAQ

What is the difference between the GH-202 and GH-252 models?
The GH-252 offers a higher sub-range capacity (101 g @ 0.01 mg) compared to the GH-202’s 51 g @ 0.01 mg; otherwise, both share identical calibration architecture, software compatibility, and compliance features.
Does the GH-202 support external calibration with user-provided weights?
No—it is designed exclusively for internal motorized calibration; external calibration is not supported or required due to its factory-traceable, self-contained reference mass system.
Can the GH-202 be integrated into a networked LIMS environment?
Yes—via RS-232C-to-Ethernet gateways or serial servers, provided the host LIMS supports ASCII-based device communication protocols and timestamp-synchronized data ingestion.
Is the date/time function battery-backed?
Yes—the internal real-time clock retains settings for up to 72 hours during power interruption, ensuring uninterrupted timestamp continuity for GLP-compliant data logging.
How frequently should internal calibration be performed?
A&D recommends initiating calibration at power-on, after significant ambient temperature shifts (>2°C), following mechanical disturbance, and at user-defined intervals—typically every 2–4 hours in regulated environments.