A&D HR-250A Entry-Level Analytical Balance

Overview

The A&D HR-250A Entry-Level Analytical Balance is a precision mass measurement instrument engineered for laboratories requiring reliable, traceable, and repeatable weighing performance at an accessible cost point. Designed and manufactured in Japan by A&D Company, Ltd.—a globally recognized leader in metrological instrumentation—the HR-250A operates on electromagnetic force restoration (EMFR) principle, delivering high reproducibility across its 252 g maximum capacity range with 0.1 mg readability. Its 2-second stabilization time ensures efficient workflow integration in routine QC, academic teaching labs, and small-scale R&D environments where throughput and regulatory compliance are equally critical. The balance meets fundamental requirements for analytical weighing under ISO/IEC 17025-accredited laboratories and supports audit-ready documentation through built-in GLP/GMP/GCP-compliant print and export functions.

Key Features

• Electromagnetic force restoration sensor architecture ensuring long-term stability and minimal drift
• 2-second stabilization time with auto-zero tracking and environmental compensation algorithms
• Removable, large-radius anti-static draft shield with rotating sliding door (198 mm × 294 mm internal chamber dimensions)
• Backlit LCD display supporting 14 selectable weighing units—including g, mg, oz, ct, and user-programmable custom units
• Internal calibration mode (HR-AZ) enabled via optional built-in reference weight; external calibration supported via standard Class M1 or E2 weights
• Dual-mode counting function with ACAI (Automatic Counting Accuracy Improvement) algorithm to enhance piece-count reliability
• Density determination capability using sinker method (requires optional density kit)
• Auto-power-off and auto-standby modes configurable via menu; real-time battery status indicator for optional rechargeable pack (HR-A09)
• RS-232C interface as standard; USB (HR-A02) and Ethernet with Win-Plus software suite (HR-A08) available as mutually exclusive options

Sample Compatibility & Compliance

The HR-250A accommodates a wide range of sample forms—including powders, granules, liquids in tared vessels, and solid specimens—within its spacious weighing chamber. Its anti-static draft shield minimizes electrostatic interference during low-mass measurements, while the smooth-surface stainless steel pan resists corrosion from common solvents and reagents. The balance complies with international metrological standards including OIML R76-1 (2017) for non-automatic weighing instruments and satisfies essential criteria for ISO 9001, ISO/IEC 17025, and pharmacopeial general chapters (e.g., USP , EP 2.1.3). All weighing events—including calibration records, zero checks, and user-defined operations—can be timestamped and exported with operator ID, enabling full traceability required under FDA 21 CFR Part 11 when used with Win-Plus software and appropriate system controls.

Software & Data Management

Data output is natively supported via RS-232C serial communication using standard ASCII protocols compatible with LIMS, ELN, and spreadsheet applications. Optional Win-Plus software (via HR-A08 Ethernet module) provides enhanced functionality: real-time graphing, statistical analysis (mean, SD, CV%, min/max), customizable report templates conforming to GLP/GMP formats, and electronic signature support for audit trails. All exported files include metadata such as date/time stamp, operator code, balance ID, ambient temperature/humidity (if connected to optional environmental sensor), and calibration status. The system supports CSV, TXT, and PDF export formats—ensuring seamless integration into regulated quality management systems.

Applications

• Quantitative preparation of standards and reference materials in pharmaceutical QC labs
• Weighing of active pharmaceutical ingredients (APIs) and excipients during formulation development
• Sample preparation for HPLC, GC, and ICP-MS analysis where sub-milligram accuracy is mandatory
• Teaching laboratory exercises in analytical chemistry and material science curricula
• Inventory control and component counting in electronics manufacturing and precision machining
• Density measurement of solids and liquids per ASTM D792 and ISO 1183 methodologies (with accessory kit)
• Moisture content determination when interfaced with halogen moisture analyzers

FAQ

What is the minimum sample weight recommended for reliable measurement on the HR-250A?

The minimum weighable quantity (MWQ) is calculated as 2,000 × readability = 200 mg, assuming a typical repeatability of 0.1 mg and a desired uncertainty ≤ 0.1%.
Does the HR-250A support internal calibration without external weights?

No—it requires external calibration weights for routine verification; however, the optional HR-AZ internal calibration function is available only when equipped with the factory-installed calibration mass.
Can multiple communication interfaces be used simultaneously?

No—USB (HR-A02), Ethernet with Win-Plus (HR-A08), and rechargeable battery (HR-A09) are mutually exclusive options due to hardware resource constraints.
Is the balance compliant with FDA 21 CFR Part 11 requirements?

Out-of-the-box, it supports audit-trail-capable data export; full Part 11 compliance requires implementation of Win-Plus software with validated system configuration, user access controls, and electronic signature workflows.
What environmental conditions affect measurement stability?

Ambient temperature fluctuations >±2°C/hour, air currents >0.2 m/s, and static charge accumulation on samples or containers may degrade repeatability—mitigated by draft shield use and grounding practices.