Sartorius ME235S Analytical Balance

Overview

The Sartorius ME235S Analytical Balance is a high-precision laboratory instrument engineered for demanding quantitative analysis in regulated and research-intensive environments. Based on electromagnetic force compensation (EMFC) technology, it delivers metrological stability and long-term repeatability under variable ambient conditions. With a 230 g capacity and 0.01 mg readability, the ME235S meets the stringent resolution requirements of pharmaceutical quality control, reference standard preparation, and analytical chemistry workflows. Its design adheres to ISO 9001 manufacturing standards and supports full traceability per ISO/IEC 17025—ensuring data integrity across calibration, operation, and reporting phases.

Key Features

• Motorized triple-sided draft shield with adaptive auto-learning: Opens/closes via palm-activated button or programmable trigger; dynamically adjusts motion profile based on environmental airflow and user frequency patterns.
• Integrated active electrostatic neutralization system: Generates balanced positive/negative ions to dissipate static charge on samples or containers—critical for low-mass powders, polymers, or glassware in dry laboratories.
• isoCAL temperature- and time-triggered internal calibration: Fully automated recalibration maintains accuracy without manual intervention; logs all events with timestamps and environmental metadata (temperature, drift rate).
• SQmin real-time USP compliance indicator: Calculates and displays the minimum sample weight required to meet USP precision thresholds (0.1% RSD), updating dynamically as weighing conditions change.
• Application-specific firmware modules: Preconfigured workflows for pipette calibration (ME235P-SD variant optimized for vertical access), formulation, density determination, percent weighing, and statistical process monitoring.
• GLP/GMP-ready data management: All operations—including tare, calibration, and result export—are timestamped, user-ID authenticated, and stored with audit trail capability compatible with FDA 21 CFR Part 11–compliant software environments.

Sample Compatibility & Compliance

The ME235S accommodates diverse sample forms—including hygroscopic solids, volatile solvents in open vessels, fine particulates, and micro-volume liquid transfers—thanks to its rapid stabilization (<8 seconds to stable 0.01 mg reading) and robust draft shield architecture. The Ø90 mm stainless-steel weighing pan ensures compatibility with standard volumetric flasks, crucibles, and custom fixtures. Regulatory alignment includes full support for ISO 17025 documentation requirements, USP and weighing validation protocols, and EU Annex 11 electronic record integrity standards. Optional Sartorius YDK printers or LabX software enable direct integration into validated laboratory information management systems (LIMS).

Software & Data Management

The ME235S operates with embedded application firmware and supports seamless bidirectional communication via RS232C. It natively exports ASCII-formatted data—including gross/net/tare values, timestamps, operator ID, and environmental parameters—to external PCs or networked printers. When paired with Sartorius LabX software (sold separately), the balance enables full electronic lab notebook (ELN) integration, automated report generation, multi-user permission controls, and 21 CFR Part 11–compliant electronic signatures. All calibration records, adjustment logs, and USP SQmin validations are retained onboard for immediate retrieval during internal audits or regulatory inspections.

Applications

• Pharmaceutical QC: Active pharmaceutical ingredient (API) assay, reference standard weighing, and USP-compliant minimum weight verification.
• Academic & industrial research: Gravimetric preparation of calibration standards, catalyst loading quantification, and nanomaterial mass characterization.
• Regulated manufacturing: In-process checks for tablet blend uniformity, coating weight distribution, and excipient dispensing accuracy.
• Pipette performance verification: Accelerated calibration cycles using the optional ME235P-SD configuration with ultra-low-profile draft shield and top-access geometry.
• Environmental testing labs: Filter weighing for PM2.5/PM10 analysis, where electrostatic mitigation and sub-0.1 mg repeatability are critical.

FAQ

Does the ME235S support automatic calibration under changing temperature conditions?
Yes—isoCAL initiates internal calibration automatically when temperature drift exceeds ±1.5 °C or at user-defined intervals (e.g., every 2 hours), ensuring continuous metrological validity.
Can the balance be integrated into a validated LIMS environment?
Yes—when used with LabX software, the ME235S provides full 21 CFR Part 11 compliance, including electronic signatures, audit trails, and role-based access control.
What is the purpose of the SQmin function?
SQmin calculates and displays the smallest sample mass that satisfies USP repeatability criteria (RSD ≤ 0.1%) given current environmental and operational conditions.
Is electrostatic neutralization mandatory for all samples?
No—it is selectively activated via dedicated front-panel key; however, it is recommended for non-conductive materials, especially below 10 mg load.
How does the motorized draft shield improve workflow efficiency?
Triple-sided opening reduces hand movement during sequential weighings; auto-learning adapts opening speed and position to minimize air turbulence and stabilize readings faster than manual shields.