METTLER TOLEDO ML Series Precision Analytical Balances

Overview

The METTLER TOLEDO ML Series comprises a family of precision analytical and semi-micro balances engineered for high reproducibility, robust mechanical stability, and seamless integration into regulated laboratory environments. Built upon the MonoBloc single-module sensor architecture, each model delivers exceptional resistance to mechanical shock and overload while maintaining traceable accuracy across its full operating range. The series adheres to fundamental principles of electromagnetic force compensation (EMFC), where sample mass is determined by the current required to restore equilibrium in a magnetic field—ensuring linearity, temperature stability, and long-term calibration integrity. Designed for routine QC, R&D, and GLP-compliant workflows, the ML balances support ISO/IEC 17025–aligned weighing practices and are routinely deployed in pharmaceutical development, chemical synthesis, materials characterization, and academic research laboratories.

Key Features

• Monobloc high-resolution electromagnetic force compensation (EMFC) transducer—eliminates mechanical linkages and enhances repeatability and drift resistance
• Backlit LCD display with intuitive icon-based interface for rapid interpretation under variable ambient lighting
• Front-mounted leveling feet with integrated bubble level indicator—enabling precise horizontal alignment without repositioning the instrument
• Dual power operation: switchable between AC mains supply and internal rechargeable battery—ideal for mobile applications or locations with unstable power infrastructure
• Integrated RS232 and USB interfaces compliant with standard CDC/ACM protocols—enabling direct, driverless data streaming to Microsoft Excel, LIMS, or ELN platforms
• Preloaded application modes—including formulation weighing, summation, dynamic weighing, piece counting, density determination (with optional accessories), checkweighing, % weighing, and statistical evaluation (mean, SD, CV, min/max)

Sample Compatibility & Compliance

The ML Series accommodates a broad spectrum of sample types—from milligram-scale reference standards and active pharmaceutical ingredients (APIs) to bulk industrial powders and packaged goods. Pan dimensions (Ø90 mm to 170 × 190 mm) and draft shield compatibility (available as optional accessory kits) ensure adaptability to volatile, hygroscopic, or static-prone materials. All models comply with international metrological requirements per OIML R76 and NIST Handbook 44. For regulated environments, firmware supports audit trail logging (when connected to compliant software), user access levels, and electronic signature readiness aligned with FDA 21 CFR Part 11 and EU Annex 11 expectations. Routine calibration verification may be performed using internal or external weights traceable to national standards (e.g., NIST, PTB, NPL).

Software & Data Management

Data export is natively supported via ASCII-formatted serial output or USB HID keyboard emulation—requiring no proprietary drivers. When paired with METTLER TOLEDO’s LabX™ Lite (freely downloadable), users gain enhanced functionality including customizable report templates, automated pass/fail logic for checkweighing, and secure database archiving with time-stamped metadata. All communication protocols are deterministic and timestamp-validated, supporting integration into enterprise systems via OPC UA or RESTful API gateways. Audit trails record operator ID, timestamp, weight value, stability status, and environmental parameters (if external sensors are connected), satisfying GLP/GMP documentation requirements.

Applications

• Pharmaceutical: Accurate dispensing of APIs during pre-formulation; content uniformity testing per USP ; tablet/capsule checkweighing
• Chemistry: Stoichiometric reagent preparation; gravimetric standard solution preparation per ISO 6497
• Materials Science: Density determination of polymers and composites using Archimedean principle (with density kit)
• Quality Control: Piece counting for fasteners, electronic components, or medical devices; statistical process control (SPC) via built-in mean/SD calculation
• Academic Research: Teaching labs requiring ISO-traceable mass measurement; method validation studies requiring documented repeatability and linearity

FAQ

What calibration options are available on the ML Series?
Internal calibration is standard on ML54, ML104, ML204, and ML802 models; ML203, ML6001, and ML303E require external calibration weights. All models support scheduled auto-calibration triggers based on time, temperature drift, or user-defined events.
Is the ML Series compatible with LIMS or ERP systems?
Yes—via RS232 or USB, the balances transmit ASCII-weight strings with configurable prefixes/suffixes (e.g., “WGT:”, “rn”). Integration with major LIMS vendors (Thermo Fisher SampleManager, LabVantage) has been validated using standard serial parsing modules.
Can I perform density measurements without additional hardware?
No—density determination requires the optional density determination kit (including sinker, thermometer, and liquid support stand), which enables ASTM D792 and ISO 1183–1 compliant measurements.
Does the balance meet IP rating requirements for lab environments?
The ML Series carries an IP42 rating—protecting against solid objects ≥1 mm and vertically falling water droplets—suitable for general laboratory use but not for wet-process or washdown applications.
How is user access controlled for compliance purposes?
While the standalone balance does not feature role-based authentication, LabX Lite enables multi-user login, permission tiers (operator, supervisor, administrator), and encrypted local storage—supporting 21 CFR Part 11 enforcement criteria when deployed on validated Windows endpoints.