Mass Comparators and Metrology from METTLER TOLEDO

    Mass Comparators

    Comparators from 0.1 µg to 6000 kg


    Mass Comparators from METTLER TOLEDO Continuous Innovation - Accompanying Your Future

    1. What is the definition of a comparator?

    A mass comparator or comparator balance is a balance with best possible resolution and repeatability allowing determining even the smallest difference is mass. While window-range mass comparators are purely used for mass calibration and mass determination, full-range mass comparators are versatile and can be used for weight determination but as well for general weighing applications where small samples meet large tare loads or the large and small amounts need to be combined in one weighing process. Contact your local METTLER TOLEDO representative to receive a GWP Recommendation identifying the models suiting your personal needs.

    2.  What makes mass calibration so different?

    In a regular weighing process, the balanced is calibrated and the individual weighing are against zero g, therefore the process is called "absolute weighing". With weight calibration, which is a specific type of differential weighing, the reference point is not the calibrated comparator balance; it's the reference weight against which the test weight is compared to. Reference weight need to be at least one weight class higher than the test weight. Each of the reference weights is again calibrated against another weight of higher class resulting to a traceability to the national prototype and finally to the International Prototype of the kilogram at the BIPM in Paris, France.

    3. What applications are comparators used for?

    The primary applications where mass comparators are used for is mass calibration. For lower class weights, in particular M 1-3, F1 & 2 classes, manual mass comparators provide results of sufficient accuracy. For weights of E1 or E2 class it is recommended to use either robotic or automated mass comparators as the measurement uncertainty is significantly lower, this mainly due to the obsolescence of the operators influence. In national metrology institutes (NMI's), which strive continuously for measurements with smallest uncertainty, vacuum or constant pressure mass comparators are utilized as these allow performing measurements at constant conditions. Influences such as geographic altitude, air buoyancy or weather conditions can be eliminated. National metrology institutes and metrology research center apply mass comparators for scientific research to measure smallest changes in mass or force.

    Besides the metrology application mass comparator are as well in use in other industries where the performance of a regular balance cannot meet the customer demand. For these applications the comparators are referred to as higher performance balances.

    Some of these industrial applications are:

    • Formulation – if tolerance levels are low and the save weighing range of the balance does not fulfil the instrument demands
    • Differential weighing applications – if the difference in mass is very small and an ordinary balance cannot provide trustworthy results
    • Gas filling – Heavy gas bottles are filled with a small amount of precious reference gas
    • Scuffing – Gears are analyzed on abrasion after the engine was run for a specified time in the lubricant of investigation
    • Force measurements – Measurements where an applied force is compensated by the weighing cell


    4. What is the difference between a mass comparator and a balance?

    Mass Comparators are of identical design and principle as an electronic balance. What differentiates the balance to the comparator is the performance, in particular the readability and repeatability.

    Regular laboratory balances are specified by the main properties repeatability (RP), eccentricity (EC), nonlinearity (NL) and sensitivity (SE). As weight calibration is subject of differential weighing mass comparators are additionally specified with differential weighing repeatability ABA (RP ABA).


    5. How to calibrate a mass comparator?

    According to regulations, Mass Comparators in use for mass calibration do not need to be calibrated, as the reference weight is calibrated and ensures for traceability to the BIPM and the definition of the kilogram. To protect your investment and ensure continuous constant measurement performance, METTLER TOELDO recommends performing preventive maintenance on a routine base.

    Where mass comparators are in use in applications different than weight calibration, it is crucial to apply existing quality standards on the XPR-C balances, identical to other analytical or precision balances.


    Vacuum Comparators
    Automated Mass Comparators
    Robotic Mass Comparators

    Vacuum Comparators

    Automated Mass Comparators

    Robotic Mass Comparators

    The world renowned Vacuum Comparators with nanogram resolution are the reference in mass determination and in use in national metrology institutes.
    Our versatile Automated Mass Comparators perform measurements automatically, resulting in extraordinary resolution and incomparable repeatability.
    Robotic solutions - extremely rapid with outstanding performance, to E1 OIML accuracy - ideal for high throughput calibration laboratories.
    Technical Specification
    Capacity up to 10 kg and Readabilty up to 0.1 µg
    International Reference
    Unrivaled repeatability to meet the need of National Metrology Institute
    Automated Weight Calibration
    Up to 6 weights, fully automated measurement
    Contamination-Free Transfer
    Load Artefacts with the Artefact Storage & Transport Vessel
    Individual Accessibility
    Through Front Window, Load-Lock
    Minimized Environmental Influences
    KLIMET A30V for ambient, constant pressure & vacuum
    Wordwide Comparison of Scientific Artefacts
    Elimination of environmental influences enables international comparison
    Technical Specification
    Capacity up to 50 kg and Readabilty up to 0.1 µg
    Unrivaled Performance
    Unmatched accuracy with uncompromizable precision
    Fully Automated Weight Handler
    Incomparable accuracy for weight dissemination
    Software Controlled
    Perform overnight measurements for best results
    Minimize Error Sources
    Eliminate errors with automatic weight handling
    Air Buoyancy Correction - Environmental Solutions
    Klimet A30 & ClimaLog30 environmental systems
    Technical Specification
    Capacity up to 20 kg and Readabilty up to 0.1 µg
    Fully Automated
    Nano-accuracy, high-speed, outstanding performance
    Maximum Efficiency
    Combine up to 4 systems to cover 0.1 µg to 20 kg
    Software Controlled
    Perform overnight measurements for best results
    Minimize Error Sources
    Eliminate errors with automatic weight handling
    Air Buoyancy Correction - Environmental Solutions
    Klimet A30 & ClimaLog30 environmental systems
    Volume, Density & Magnetism
    Manual Mass Comparators

    Systems for Volume, Density & Magnetism

    Manual Mass Comparators

    ComparatorPac ™

    Simple and reliable solutions for volume, density and magnetism determination - meeting the highest requirements of National Metrology Institutes.
    The combination of a highly ergonomic user interface with the menu-guided mass determination software simplifies and improves every operator’s work.
    A complete package of Comparators and Software - ComparatorPac™ is the ideal starter solution for simple weight calibration up to 20 kg OIML F2.
    Technical Specification
    Volume & Density: 1 g to 20 kg Magnetism: 1 g to 50 kg
    Determine Volume, Density & Magnetism of Weights
    VMS for Density and Mass Determination
    Using standard XPE comparators - simple & reliable
    VC1005X - 1 g to 1 kg
    Fast & accurate density measurements down to 1 g
    S50-K Susceptometer
    Simple and cost-effective magnetism determination
    Guided Workflows
    Software control for operation & results handling
    Technical Specification
    Capacity up to 5000 kg and Readabilty up to 0.1 µg
    High Performance
    Top class weighing cell & leveling systems
    Handsfree operation of Draftshields
    Control draftshields with MC Link Software or SmartSens™
    Safe & Faster Weight Calibration
    No manual transcription due to MC Link
    MC Link guiding & controlling the process
    Smooth process by on-screen guidance
    Environment Recording
    Klimet A30 & ClimaLog30 environmental systems
    Technical Specification
    3 XPE comparators and MC Link Software
    All-in-one Offering
    Cost-effective starter package
    Package suitable to your local needs
    Productivity Booster
    MC Link One-Click weight calibration software included
    Simplified Facility Validation
    Prevalidated software supporting smooth approval
    Efficient Workflow
    Increase the calibration process speed by up to 40%
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