METTLER TOLEDO XPR Micro Balance

Overview

The METTLER TOLEDO XPR Micro Balance is an ultra-high-precision weighing instrument engineered for trace-level mass determination in regulated laboratory environments. Based on electromagnetic force compensation (EMFC) technology, the XPR series delivers metrological stability and resolution down to 0.1 µg — enabling accurate quantification of nanogram-to-milligram sample masses essential in pharmaceutical development, reference standard preparation, catalyst research, and forensic trace analysis. Its monolithic sensor architecture, active temperature control, and adaptive vibration compensation ensure consistent performance under variable ambient conditions. Designed and manufactured in Switzerland, each XPR unit undergoes individual calibration and verification against national metrology institute standards prior to shipment, fulfilling ISO/IEC 17025 traceability requirements. The balance operates within a defined environmental envelope (temperature stability ±0.5 °C, humidity 30–60% RH non-condensing), and its internal diagnostics continuously monitor drift, draft interference, and mechanical integrity to maintain measurement confidence.

Key Features

• Ultra-low readability options: 0.1 µg (XPR2U/XPR6U) to 1 µg (XPR10/XPR3), supporting critical applications where mass uncertainty must remain below 0.1% RSD.
• SmartView auxiliary display: A secondary, remotely positioned screen provides real-time weight values and status indicators without requiring operator repositioning — reducing workflow interruption and contamination risk during glove-box or laminar flow hood operations.
• Active temperature control (ATC): Integrated Peltier elements stabilize the weighing cell at a constant temperature independent of lab fluctuations, minimizing thermal drift and enhancing long-term repeatability.
• ProMode™ intelligent weighing mode: Automatically selects optimal filtering, settling time, and damping parameters based on sample behavior and environmental input, improving throughput without compromising accuracy.
• Compact footprint with ergonomic height: Optimized for integration into fume hoods, isolators, and automated workstations; base dimensions as small as 205 × 330 mm (W × D).
• Full compliance with USP , , and EP 2.1.6: Built-in minimum weight calculation, automatic recalibration prompts, and audit-ready reporting tools support GLP/GMP documentation workflows.

Sample Compatibility & Compliance

The XPR micro balance accommodates diverse sample forms — including powders, crystals, thin films, micro-pellets, and volatile organics — when used with appropriate draft shields (e.g., XPR-specific SmartShield™ with auto-sensing door detection). All models comply with international regulatory frameworks: FDA 21 CFR Part 11 (electronic records/signatures), EU Annex 11, and ISO 9001 quality management requirements. Internal validation protocols generate IQ/OQ documentation templates aligned with ASTM E898 and EURAMET cg-18 guidelines. Each unit ships with a factory-issued calibration certificate traceable to PTB (Physikalisch-Technische Bundesanstalt) or NIST standards, and supports user-performed performance verification per USP using certified reference weights (e.g., Class E2 or better).

Software & Data Management

XPR balances integrate seamlessly with METTLER TOLEDO LabX® software — a centralized, server-based platform for method management, electronic batch records, and automated data archiving. LabX enforces role-based access control, full audit trail logging (including all weight events, parameter changes, and calibration actions), and configurable electronic signatures compliant with 21 CFR Part 11. Data export supports CSV, PDF, XML, and direct LIMS/SAP connectivity via OPC UA or ODBC. Optional Good Manufacturing Practice (GMP) modules provide deviation tracking, change control workflows, and periodic review reports required for regulatory inspections. All firmware updates are digitally signed and verified to prevent unauthorized modification.

Applications

• Pharmaceutical: Weighing of potent active pharmaceutical ingredients (APIs), reference standards, and placebo formulations where ≤0.1% mass error is mandatory.
• Materials science: Quantification of nanomaterial dispersions, catalyst loading on substrates, and thin-film deposition mass gain/loss studies.
• Academic research: Isotope ratio mass spectrometry (IRMS) sample preparation, radiolabeled compound handling, and microgravimetric corrosion testing.
• Forensics & toxicology: Trace evidence weighing (e.g., drug residues, gunshot residue particles) under chain-of-custody protocols.
• Chemical synthesis: Accurate dispensing of expensive reagents (e.g., chiral ligands, organometallics) to minimize waste and improve reaction reproducibility.

FAQ

What is the smallest sample mass that can be weighed with statistical reliability?

The minimum weight is calculated per USP and ranges from 0.3 mg (XPR2U) to 1.0 mg (XPR3), depending on model-specific repeatability and required uncertainty threshold.

Does the XPR support automated calibration with external weights?

Yes — all XPR models feature motorized internal calibration mechanisms and optional external weight calibration routines with full traceability logging.

Can the balance be validated for GxP environments?

Absolutely — built-in validation tools, IQ/OQ templates, and LabX-supported PQ execution enable full lifecycle validation per GAMP 5 and Annex 15.

Is the 7″ touchscreen compatible with gloved operation?

Yes — the capacitive display supports multi-touch gestures and responds reliably even with standard nitrile or latex gloves.

How does the XPR handle electrostatic interference during micro-weighing?

Integrated ionizer port compatibility (with optional METTLER TOLEDO StaticDetect™) and grounded weighing pan design mitigate static-induced errors common with low-mass insulating samples.