Shimadzu BX-K/BW-K Series Medium-Precision Benchtop Balances

Overview

The Shimadzu BX-K/BW-K Series represents a class of medium-precision benchtop balances engineered for high-reliability mass measurement in regulated industrial, pharmaceutical, and quality control laboratories. Designed around Shimadzu’s proprietary Uni Bloc monolithic load cell architecture, these balances deliver exceptional mechanical stability—minimizing sensitivity drift caused by thermal expansion or mechanical deformation during extended operation. The series comprises two functional variants: the BX-K models, optimized for external calibration workflows, and the BW-K models, integrating an internal calibration mass (up to 5.6 kg) for rapid, operator-initiated sensitivity verification without manual weight handling. All units feature built-in real-time clock functionality, ISO-compliant print output, and native RS-232C connectivity—enabling seamless integration into laboratory information management systems (LIMS) and electronic record-keeping environments governed by FDA 21 CFR Part 11, EU Annex 11, and GLP/GMP documentation requirements.

Key Features

• Uni Bloc Load Cell Technology: A single-piece aluminum alloy sensing element ensures long-term linearity, repeatability, and resistance to off-center loading effects—critical for consistent performance across varying environmental conditions.
• Internal Calibration (BW-K Models): Integrated motor-driven calibration mass enables one-touch sensitivity verification at user-defined intervals, eliminating dependency on external weights and reducing procedural variability.
• Direct Data Transmission: Pre-installed communication protocol and Windows-compatible driver allow immediate export of measurement data—including tare values, net weights, timestamps, and statistical summaries—to Excel and other Windows-based applications using only a standard RS-232C cable.
• GLP/GMP-Ready Documentation: Automatic timestamping (date + time) of calibration events and measurement records supports full audit trail generation. When paired with EP-80 or EP-50WIN printers, all outputs include traceable metadata required for regulatory submissions.
• Flexible Operating Modes: Supports multiple weighing modes—including piece counting, percentage weighing, density determination (with optional accessories), dynamic interval weighing, and克拉 (carat) measurement—configurable via intuitive front-panel navigation.
• Portable Operation: Optional rechargeable battery pack (model 321-61691-01) enables up to 8 hours of continuous use in field or mobile lab settings, with full functionality retained including clock synchronization and data logging.

Sample Compatibility & Compliance

The BX-K/BW-K Series accommodates a broad range of sample types—from bulk industrial materials (e.g., powders, granules, packaged goods) to precision components requiring kg- or g-level resolution. The large 345 mm × 250 mm weighing pan facilitates stable placement of irregular or oversized items, while the low-profile housing design improves ergonomics during frequent loading/unloading cycles. Units comply with international metrological standards including OIML R76-1 (2006) and JIS B 7721-1:2014 for non-automatic weighing instruments. All firmware and data-handling routines are designed to meet ISO/IEC 17025:2017 clause 7.7 (result reporting) and support validation protocols aligned with USP , ASTM E899, and ICH Q7 Annex 19. Calibration history, user ID (where enabled), and environmental condition logs (via optional sensors) can be embedded in exported datasets for full analytical traceability.

Software & Data Management

No third-party software installation is required: the balance ships with embedded serial communication firmware and a preconfigured Windows driver supporting plug-and-play connectivity. Measurement data—including gross, net, tare, count, and statistical parameters (mean, SD, CV%)—is transmitted in ASCII format compatible with Excel, LabVIEW, and custom LIMS interfaces. Timestamps are synchronized with the internal real-time clock (RTC), ensuring temporal integrity across multi-user environments. For regulated operations, the EP-50WIN software package provides enhanced features including electronic signature capture, role-based access control, and automated PDF report generation compliant with 21 CFR Part 11 Annex A requirements. All calibration actions generate immutable audit log entries stored onboard and mirrored in printed or exported records.

Applications

• Pharmaceutical manufacturing: Raw material receipt inspection, batch formulation checks, and packaging line verification under GMP Annex 8 and WHO TRS 986.
• Food & beverage QC labs: Portion control validation, ingredient reconciliation, and shelf-life study sample tracking.
• Materials testing labs: Density determination of polymers and composites (using optional density kit), powder flow characterization via mass-based feeder calibration.
• Automotive and electronics assembly: Component counting, solder paste dispensing verification, and sub-assembly weight tolerance screening.
• Academic research facilities: Teaching labs requiring robust, multi-mode instrumentation for metrology education and method development.

FAQ

Does the BW-K series require periodic recalibration with external weights?
No—BW-K models perform automatic internal calibration using the integrated 5.6 kg reference mass. External verification with traceable standards is recommended annually or per internal SOP, but daily operational calibration is fully autonomous.
Is the RS-232C interface compatible with modern Windows 10/11 systems?
Yes—provided the system includes a USB-to-RS-232 adapter and the included Shimadzu driver is installed. Native COM port enumeration is supported; no virtual COM emulation is necessary.
Can the balance operate continuously on battery power during GLP audits?
Yes—the battery pack maintains full functionality including RTC synchronization, data logging, and printer communication. Runtime is verified at ≥8 hours under typical 1-second sampling intervals.
What documentation is provided for IQ/OQ/PQ validation?
Shimadzu supplies a comprehensive validation support package including URS templates, test protocols for linearity, repeatability, eccentricity, and sensitivity, as well as a factory calibration certificate traceable to NMIJ (Japan) and NIST (USA).
Is density determination possible without additional hardware?
No—density mode requires optional accessories: a density determination kit (including immersion fixture and sinker) and calibrated reference liquid (e.g., distilled water at 20 °C). The balance firmware supports automatic calculation per ISO 1183-1.