METTLER TOLEDO XPR Series Micro and Ultra-Micro Balances

Overview

The METTLER TOLEDO XPR Series represents the engineering culmination of over six decades of precision mass measurement innovation. Designed for laboratories where sample scarcity, cost sensitivity, or regulatory stringency define operational constraints, these micro and ultra-micro balances operate on electromagnetic force compensation (EMFC) principle — delivering stable, drift-resistant measurements under dynamic environmental conditions. With readability down to 0.001 mg (1 µg) and maximum capacities ranging from 2.1 g to 22 g, the XPR platform serves as a metrological anchor in applications demanding traceable, repeatable, and legally defensible mass data. Each instrument is manufactured in Greifensee, Switzerland, and undergoes individual calibration against national standards prior to shipment — ensuring conformance with ISO/IEC 17025 requirements for accredited calibration laboratories.

Key Features

• SmartScreen TFT Color Touch Interface: A 5.7-inch high-resolution display with intuitive icon-based navigation and multilingual support — including English, German, French, Spanish, Chinese, and Japanese — enables rapid method execution and reduces operator training time.
• SmartSens Infrared Sensors: Contactless operation for door control, tare, print, and menu navigation minimizes mechanical wear and eliminates cross-contamination risks during handling of cytotoxic, radioactive, or hygroscopic materials.
• SmartGrid Draft Shield System (XPR26/XPR56 only): A patented grid-patterned weighing chamber design accelerates stabilization by optimizing airflow dynamics — reducing settling time by up to 40% compared to conventional enclosed chambers.
• LevelControl Active Leveling Assistant: Integrated tilt sensors continuously monitor horizontal alignment; visual and audible alerts prompt immediate correction before measurement initiation — preventing systematic error due to gravitational vector misalignment.
• proFACT Dual-Trigger Calibration: Fully automated internal calibration initiated either by predefined time intervals or real-time temperature deviation detection (±1.5 °C), including simultaneous linearization across the full span — eliminating manual recalibration labor and guaranteeing long-term accuracy stability.
• GWP® Excellence Built-in Risk Management: Real-time assessment of environmental impact, usage patterns, and performance history generates actionable maintenance alerts and certifies operational fitness per Good Weighing Practice guidelines.

Sample Compatibility & Compliance

The XPR Series accommodates diverse sample forms — powders, crystalline solids, volatile organics, nanomaterials, and biological extracts — without compromising resolution or repeatability. All models comply with pharmacopeial requirements for minimum weight determination (USP and ), enabling automatic MinWeigh validation when configured with certified reference weights and validated by METTLER TOLEDO Field Service Engineers. Data integrity is enforced via built-in audit trail functionality compliant with FDA 21 CFR Part 11, EU Annex 11, and ISO 13485. Full traceability includes timestamped operator ID, balance ID, environmental parameters (temperature/humidity logs), calibration history, and raw measurement metadata — exportable in CSV, PDF, or XML formats compatible with LIMS and ELN systems.

Software & Data Management

LabX™ software provides centralized control, method management, and secure data archiving for multi-balance networks. It supports role-based access control, electronic signatures, and configurable electronic batch records aligned with GMP Annex 11. For standalone use, the onboard balance software offers customizable report templates with embedded digital signatures, configurable pass/fail criteria, and direct export to network drives or cloud storage via Ethernet or USB. All communication interfaces — RS232, USB, Ethernet, Bluetooth, LocalCAN, and PS/2 — are supported through a hot-swappable interface module, allowing seamless integration into legacy QC workflows or modern Industry 4.0 laboratory infrastructures.

Applications

These balances serve critical roles across regulated and research-intensive domains: standard substance weighing in pharmaceutical QC labs (e.g., reference standards for HPLC assay validation); filter mass differential analysis in automotive emissions testing (ISO 8573-1 particulate quantification); precious metal recovery assays in metallurgical R&D; catalyst loading verification in fine chemical synthesis; and nanogram-level formulation dosing in biopharmaceutical lyophilization development. Their low minimum weighing values make them indispensable for toxicology studies involving radiolabeled compounds and forensic trace evidence quantification.

FAQ

What is the difference between readability and repeatability in XPR balances?

Readability refers to the smallest digit displayed (e.g., 0.001 mg), while repeatability defines the standard deviation of repeated measurements under identical conditions — typically ≤ ±0.001 mg for ultra-micro configurations.
Is external calibration required after proFACT internal calibration?

Yes — periodic external calibration using traceable NIST- or BIPM-certified weights remains mandatory for ISO/IEC 17025 accreditation; proFACT ensures intermediate stability but does not replace formal calibration cycles.
Can MinWeigh be activated remotely?

No — MinWeigh configuration requires on-site validation by a METTLER TOLEDO-certified service engineer to verify environmental conditions, draft shield integrity, and weight set traceability.
Does XPR support GLP-compliant electronic record retention?

Yes — all measurement events, user actions, and system diagnostics are logged with immutable timestamps and exported in tamper-evident formats meeting ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).
How does SmartGrid improve weighing speed in XPR26/XPR56 models?

By replacing solid side panels with aerodynamically optimized perforated grids, SmartGrid reduces turbulent eddies inside the chamber — accelerating air displacement and shortening stabilization time without sacrificing dust or moisture protection.