METTLER TOLEDO ML Series Analytical Balance

Overview

The METTLER TOLEDO ML Series Analytical Balance is a high-precision mass measurement instrument engineered for routine laboratory applications requiring reliable 0.1 mg readability and robust metrological performance. Built upon METTLER TOLEDO’s proprietary MonoBloc weighing cell technology, the ML Series integrates a single-piece sensor architecture that eliminates mechanical play and thermal drift—ensuring long-term stability, exceptional shock resistance, and consistent repeatability (≤0.1 mg standard deviation) across varying environmental conditions. Designed and manufactured in Switzerland, each unit adheres to stringent ISO 9001 quality management standards and meets the fundamental requirements of ISO/IEC 17025 for calibration laboratories. The balance operates on the principle of electromagnetic force compensation (EMFC), where the mass-induced displacement of the weighing pan is counteracted by a precisely regulated current; this current is directly proportional to the applied mass and digitally converted into a stable, traceable reading.

Key Features

• Monobloc single-module weighing cell: Delivers superior mechanical integrity, minimizes sensitivity to vibration and overload events, and ensures metrological consistency over time.
• Backlit LCD display with intuitive icon-driven interface: Enables rapid interpretation of results under ambient lighting conditions—including bright laboratory environments—without compromising legibility or contrast.
• Eight built-in application modes: Supports foundational operations (e.g., gross/net/tare), statistical evaluation (mean, SD, CV, min/max), piece counting, percentage weighing, density determination (with optional density kit), dynamic (moving-object) weighing, checkweighing, and history recall of up to 99 previous results.
• Dual power configuration: Operates seamlessly via included AC adapter or eight AA batteries, providing up to eight hours of continuous use—ideal for mobile lab workflows or locations with unstable mains supply.
• Standard digital interfaces: Equipped with both RS232 and USB ports for direct data transmission to LIMS, ELN, or spreadsheet applications such as Microsoft Excel—enabling automated documentation without manual transcription.

Sample Compatibility & Compliance

The ML Series accommodates standard analytical samples within its Ø90 mm stainless-steel weighing pan, optimized for compatibility with common crucibles, weighing boats, and volumetric glassware. Its compact footprint and draft shield–compatible design support integration into fume hoods and controlled-environment workstations. From a regulatory standpoint, the balance supports Good Laboratory Practice (GLP) and Good Manufacturing Practice (GMP) workflows when paired with the optional RS-P26 thermal printer: timestamped, user-identified printouts comply with core elements of FDA 21 CFR Part 11 (electronic records and signatures) and EU Annex 11, provided system validation protocols—including user access control, audit trail activation, and electronic signature implementation—are executed per organizational SOPs.

Software & Data Management

Data export follows standardized ASCII protocols over RS232 or HID-compliant USB, enabling plug-and-play integration with third-party laboratory software. No proprietary drivers are required. When connected to validated enterprise systems, the ML Series supports full traceability—including operator ID, date/time stamp, balance ID, and raw weight values—with no post-acquisition manipulation. Optional firmware updates (available via METTLER TOLEDO’s official support portal) maintain alignment with evolving metrological guidance, including EURAMET cg-18 and OIML R 76 recommendations for non-automatic weighing instruments.

Applications

The ML Series serves as a primary mass reference in QC/QA labs for pharmaceutical dosage form testing (per USP ), chemical reagent preparation, catalyst loading verification, and formulation development. It is routinely deployed in academic research for gravimetric analysis, titrant standardization, and sample aliquoting prior to ICP-MS or HPLC injection. In food safety testing, it supports AOAC 990.11 moisture content determinations and ISO 5725-based method validation studies. Its internal calibration capability—activated at user-defined intervals or temperature thresholds—ensures uninterrupted compliance during extended shift operations.

FAQ

What calibration options are available on the ML Series?
Internal calibration is standard across all models (ML54, MS104, MS204); no external weights are required for routine adjustment. Calibration frequency can be scheduled manually or triggered automatically based on temperature change thresholds.
Is the ML Series compliant with ISO/IEC 17025?
Yes—the instrument’s documented metrological characteristics (repeatability, linearity, eccentricity, and sensitivity) satisfy clause 6.4.10 of ISO/IEC 17025:2017 for equipment used in accredited testing laboratories.
Can the balance store weighing data internally?
It retains the last 99 weighing results in volatile memory; persistent storage requires external transfer via RS232 or USB.
Does the ML Series support multi-user authentication?
User identification is managed externally via connected software; the balance itself does not feature onboard user accounts or password protection.
What environmental conditions affect performance?
Operation is specified for 10–30 °C ambient temperature and ≤80 % RH (non-condensing). Draft shields and anti-vibration tables are recommended in environments exceeding 0.5 m/s air velocity or exhibiting floor-borne mechanical noise.