METTLER TOLEDO XPR Micro and Ultra-Micro Balance

Overview

The METTLER TOLEDO XPR series represents the benchmark in ultra-micro and micro balance technology for laboratories demanding trace-level mass measurement with uncompromising metrological integrity. Engineered for applications where sample scarcity, regulatory scrutiny, or process-critical decision-making govern analytical workflows—such as reference standard preparation, nanomaterial dosing, catalyst loading, and high-potency active pharmaceutical ingredient (HPAPI) formulation—the XPR platform employs a proprietary electromagnetic force compensation (EMFC) sensor architecture integrated with Active Temperature Control (ATC™). This dual-thermal-management system stabilizes the sensor’s internal temperature to ±0.1 °C, minimizing thermal drift and enabling consistent sub-microgram repeatability even under ambient fluctuations. Unlike conventional balances relying solely on passive shielding, the XPR’s ATC™ ensures that sensor performance remains decoupled from laboratory HVAC cycles, delivering stable readability of 0.1 µg across its 2.1 g maximum capacity range. The design adheres to fundamental metrological principles defined in OIML R 76 and EU Directive 2014/31/EU, with all models factory-calibrated using traceable NIST-traceable weights and validated per GWP® (Good Weighing Practice) methodology.

Key Features

• Active Temperature Control (ATC™): Real-time thermal stabilization of the EMFC sensor core, reducing temperature-induced drift to ≤0.0001 %/°C and ensuring long-term stability of ≤0.0001 %/year.
• proFACT Fully Automatic Calibration & Leveling: Dual-motorized internal calibration mass deployment triggered by time, temperature change (>1.5 °C), or user command; integrated LevelControl™ provides graphical, step-by-step leveling guidance via touchscreen.
• SmartView™ Secondary Terminal: Mountable directly above the draft shield, providing immediate access to tare, print, method execution, and StatusLight™ feedback without reaching into the weighing chamber.
• Capacitive Touchscreen Interface: Glove-compatible, multi-touch responsive display with swipe navigation, customizable home screen, and embedded SOP method library supporting parameter locking and user-specific access levels.
• GWP® Verification Integration: Embedded quality assurance engine continuously monitors critical performance parameters—including repeatability, linearity, eccentricity, and sensitivity shift—against user-defined tolerance profiles; StatusLight™ turns green only when all criteria are met.
• ErgoSens™ Infrared Gesture Control: Hands-free draft shield operation via motion detection, minimizing contamination risk during sterile or cytotoxic workflows.
• MinWeigh™ Function: Dynamic lower-limit warning based on current environmental conditions and measured repeatability, compliant with USP and ASTM E897 minimum weight requirements.

Sample Compatibility & Compliance

The XPR series accommodates diverse sample forms—including powders, crystals, filters (47 mm and 70 mm), microtubes, and thin-film substrates—via optional accessories such as the Filter Weighing Kit, Tube Holder Weighing Pan, and Anti-Static Kit (part no. 30215452). All configurations maintain full compliance with Good Laboratory Practice (GLP) and Good Manufacturing Practice (GMP) documentation requirements. Audit trails record every calibration event, adjustment, user login, method modification, and weighing result with immutable timestamps and operator ID. Data integrity conforms to FDA 21 CFR Part 11 through role-based password protection, electronic signatures, and configurable retention policies. The balance supports IQ/OQ/PQ validation protocols and is prequalified for use in environments governed by ICH Q7, ISO 13485, and EU Annex 11.

Software & Data Management

XPR balances operate natively with METTLER TOLEDO’s LabX® software suite, enabling centralized instrument management, automated report generation, and seamless LIMS/ERP integration via OPC UA or direct database export. Local data storage includes an embedded notebook logging all parameters, results, metadata (e.g., ambient T/RH, draft shield status), and operator annotations. Four USB-A ports support printers, barcode scanners, and peripheral storage; one Gigabit Ethernet port enables networked deployment and remote diagnostics. All data exports comply with CSV, PDF/A-1, and XML formats validated for regulatory submission. Firmware updates are digitally signed and verified prior to installation to ensure cryptographic integrity.

Applications

• Pharmaceutical Development: Accurate dispensing of nanogram-to-milligram reference standards for assay validation and stability studies.
• Materials Science: Precise mass dosing of catalysts, quantum dots, and metal-organic frameworks (MOFs) where stoichiometric fidelity impacts reaction yield.
• Environmental Analysis: Gravimetric determination of particulate matter (PM₂.₅/PM₁₀) on quartz or Teflon filters per EPA Method 201A and ISO 12103-1.
• Academic Research: Isotope labeling experiments requiring sub-µg quantification of enriched compounds in tracer kinetics.
• Quality Control Labs: Routine verification of tablet coating uniformity, excipient blend homogeneity, and lyophilized vial fill weight consistency.

FAQ

What is the smallest mass the XPR2U can weigh with USP compliance?
The XPR2U achieves a USP-compliant minimum weight of 0.3 mg (k=2, U=0.1%) under standard lab conditions (23 °C ±2 °C, 50% RH ±10%).
Does the XPR support GLP-compliant audit trail generation?
Yes—every user action, calibration event, result entry, and configuration change is timestamped, attributed, and cryptographically logged in a non-erasable format meeting 21 CFR Part 11 requirements.
Can the SmartView terminal be mounted outside a fume hood or safety cabinet?
Yes—the modular terminal cable (4.5 m length, part no. 30300920) allows remote placement while maintaining full functionality and real-time synchronization with the main unit.
How does proFACT differ from standard internal calibration?
proFACT combines automatic motorized calibration mass deployment with simultaneous auto-leveling and temperature-triggered recalibration—eliminating manual intervention and ensuring continuous metrological readiness.
Is the ATC™ system active during weighing or only during standby?
ATC™ operates continuously—both during active weighing and idle periods—to maintain sensor thermal equilibrium at all times, thereby guaranteeing consistent repeatability regardless of measurement frequency.