Sartorius BSA-CW Series Automatic Internal Calibration Precision Balance

Overview

The Sartorius BSA-CW Series is a line of high-precision analytical and semi-micro balances engineered for laboratories requiring traceable, repeatable mass measurement under routine and regulated conditions. Built upon Sartorius’ monolithic electromagnetic force compensation (EMFC) transducer architecture, each model delivers stable, drift-resistant performance by continuously balancing the gravitational force on the sample against a precisely controlled electromagnetic counterforce. This principle ensures inherent linearity, temperature independence, and long-term stability—critical for applications governed by ISO/IEC 17025, USP , and FDA 21 CFR Part 11 requirements. The integrated motor-driven internal calibration system (CW = “Calibration Weight”) eliminates manual intervention, automatically initiating calibration at user-defined intervals or in response to environmental triggers (e.g., temperature shift ≥1.5 °C), thereby maintaining continuous metrological traceability without disrupting workflow.

Key Features

• Motorized internal calibration with certified built-in weights traceable to national standards (e.g., PTB, NIST)
• Front-mounted bubble level and automatic leveling assistance for rapid setup and positional integrity verification
• Five-sided anti-static glass draft shield with conductive coating—reduces electrostatic interference by >95% per IEC 61340-5-1
• High-speed 40 MHz microcontroller (MC1) enabling sub-second stabilization times and real-time dynamic filtering
• Advanced SMT-based electronics architecture minimizing thermal drift and cross-talk between analog/digital domains
• Dual tare keys (left/right placement) supporting ergonomic operation in multi-user environments
• Bottom-loading hook for density determination, magnetic susceptibility testing, and large-volume sample weighing
• Four-stage mechanical damping system compliant with ISO 17025 Annex A.4 for vibration-prone laboratory locations

Sample Compatibility & Compliance

The BSA-CW series accommodates diverse sample forms—from fine powders and volatile solvents to irregularly shaped solids—within its optimized draft shield geometry and wide pan dimensions (up to 180 × 180 mm). All models meet European Measuring Instruments Directive (MID) Class II accuracy requirements and are CE-marked for legal-for-trade use where applicable. Firmware and hardware design comply with GLP data integrity principles: full audit trail logging (including calibration events, tare actions, and error codes), time-stamped RS232 output with configurable delimiter formats, and non-volatile memory retention of up to 1,000 measurement records. Optional Q-App software enables secure electronic signature integration and 21 CFR Part 11–compliant user access control.

Software & Data Management

RS232 serial interface supports direct connection to LIMS, ELN, or statistical process control (SPC) platforms without middleware. Output includes raw mass value, unit, timestamp, operator ID (if enabled), and status flags (e.g., “CALIBRATING”, “OVERLOAD”). Sartorius DataControl software (sold separately) provides automated report generation aligned with ISO 10012 and ASTM E1169, including uncertainty budgeting per GUM (JCGM 100:2008). All firmware updates are digitally signed and verified during installation to ensure cryptographic integrity—a prerequisite for GxP-regulated environments.

Applications

• Quantitative formulation in pharmaceutical development (e.g., active ingredient dispensing per USP )
• Gravimetric preparation of reference standards and calibration solutions
• Density determination of solids and liquids using the built-in density application (ASTM D792, ISO 1183)
• Counting small components (e.g., tablets, screws, PCB parts) with statistical confidence interval calculation
• Animal weighing with dynamic averaging to suppress motion-induced noise
• Percent weighing for formulation scaling and batch reconciliation
• Net weight summation across multiple containers for inventory control
• Custom arithmetic operations (e.g., multiplication/division of measured values) for yield calculations

FAQ

How does the internal calibration system maintain traceability?
The motorized calibration mechanism engages certified internal weights whose mass values are factory-characterized against primary standards and stored in encrypted EEPROM. Each calibration cycle generates a digital certificate containing date/time, ambient temperature, deviation values, and cryptographic hash—exportable via RS232.
Is the balance compatible with regulated quality systems?
Yes. Firmware supports ALCOA+ data attributes (Attributable, Legible, Contemporaneous, Original, Accurate) and enforces role-based access control when paired with Sartorius Q-App. Audit trails are immutable and exportable in CSV/PDF.
What environmental conditions affect repeatability?
Air currents, static charge, and thermal gradients remain primary variables. The anti-static shield, front-level indicator, and 4-stage damping mitigate these; however, operation within ±2 °C of calibration temperature is recommended for ≤±1 mg repeatability.
Can the balance be integrated into an automated lab system?
Yes. RS232 protocol supports SCPI command set for remote triggering of weighing, tare, calibration, and data readout—enabling seamless integration with robotic arms, conveyors, or PLC-controlled workflows.
Does the BSA-CW series support density determination of porous materials?
Yes. When used with Sartorius’s optional density kit (including sinker, thermometer, and hydrometer stand), the balance executes ASTM D5364-compliant procedures for apparent density, true density, and open/closed porosity calculations.