METTLER TOLEDO XS Micro Balance
| Brand | METTLER TOLEDO |
|---|---|
| Origin | Switzerland |
| Model | XS Series Micro Balance |
| Maximum Capacity | 3.1 g |
| Readability | 1 µg |
| Minimum Weight (USP) | 1.0 mg |
| Repeatability (typ.) | ≤0.8 µg |
| Operating Temperature Range | 18–25 °C |
| Environmental Stability Requirement | ±0.5 °C/h, <30% RH change/h |
| Interface Options | RS232, USB, Ethernet (optional), Bluetooth (optional) |
| Compliance | USP <41>, <1251>, ISO/IEC 17025, ASTM E898, GLP/GMP-ready with audit trail capability |
Overview
The METTLER TOLEDO XS Micro Balance is an entry-level ultra-micro weighing system engineered for laboratories requiring sub-milligram mass determination with high reproducibility and regulatory traceability. Based on electromagnetic force compensation (EMFC) technology, the XS series delivers stable, drift-compensated measurements at a readability of 1 µg — enabling precise quantification of active pharmaceutical ingredients (APIs), reference standards, catalysts, and nanomaterials. Unlike conventional analytical balances, the XS platform integrates adaptive environmental monitoring and real-time drift correction algorithms to maintain measurement integrity under typical lab conditions (18–25 °C, <30% RH/h variation). Its compact monolithic sensor architecture minimizes mechanical hysteresis and thermal lag, supporting consistent performance across daily calibration cycles without mandatory recalibration after minor temperature fluctuations.
Key Features
- 1 µg readability with ≤0.8 µg repeatability (typ.) — validated per USP protocol using calibrated 1 mg test weights
- Automatic internal calibration with motorized mass actuator; scheduled or event-triggered (e.g., door opening, temperature shift >0.5 °C)
- Touchscreen interface with guided weighing workflows — including USP-compliant minimum weight verification, tare sequence logging, and step-by-step SOP prompts
- Integrated draft shield with electrostatic discharge (ESD)-safe polymer panels and low-turbulence airflow design to suppress convection artifacts during sub-milligram operations
- Modular connectivity: Standard RS232 and USB Device ports; optional Ethernet (for networked LabX integration) and Bluetooth 5.0 (for wireless tablet pairing)
- GLP/GMP-compliant data handling: Full audit trail with user ID, timestamp, weight value, stability flag, environmental metadata (T/RH), and calibration history — exportable as PDF or CSV with digital signature support
Sample Compatibility & Compliance
The XS Micro Balance accommodates samples ranging from 1 µg to 3.1 g, with optimal accuracy achieved between 1 mg and 3 g. It supports standard weighing vessels (e.g., aluminum sample pans, glass vials, quartz microcrucibles) and is compatible with static-dissipative accessories for electrostatic-prone powders. All operational parameters comply with United States Pharmacopeia chapters (Weights and Balances) and (Analytical Instrument Qualification), ensuring suitability for QC release testing in pharmaceutical manufacturing. The balance meets ISO/IEC 17025 requirements for accredited testing laboratories and supports 21 CFR Part 11 compliance when deployed with METTLER TOLEDO LabX software (version 3.6+), including electronic signatures, role-based access control, and immutable record retention.
Software & Data Management
Data acquisition and reporting are managed via embedded firmware or integrated LabX software. The onboard system stores up to 1,000 weighing records with full environmental context and calibration status flags. LabX enables centralized instrument management across multi-balance networks, automated report generation (including USP minimum weight pass/fail summaries), and direct LIMS/ERP integration via ODBC or REST API. Audit trails are cryptographically hashed and time-stamped by an internal hardware clock synchronized to NTP servers. Raw data files include metadata headers compliant with ASTM E898-22 (Standard Guide for Data Exchange in Analytical Chemistry), facilitating third-party validation and regulatory submission.
Applications
- Pharmaceutical: Quantitative assay of potent APIs, residual solvent analysis standards, blend uniformity sampling
- Materials Science: Weighing of catalyst nanoparticles, thin-film deposition precursors, and quantum dot dispersions
- Environmental Testing: Preparation of certified reference materials (CRMs) for trace metal analysis (e.g., ICP-MS calibration standards)
- Academic Research: Gravimetric synthesis monitoring, isotope-labeled compound dosing, and microcalorimetry sample loading
- Quality Control: USP -mandated balance verification, repeatability testing, and minimum weight validation per batch
FAQ
What is the smallest sample mass reliably measurable on the XS Micro Balance?
The validated minimum weight per USP is 1.0 mg — determined using a 1 mg certified reference weight and ≥10 replicate measurements under controlled environmental conditions.
Does the XS series support external calibration with traceable weights?
Yes. The balance accepts external calibration via Class E2 or better weights (ISO 9001-certified), with full documentation of deviation, adjustment factor, and uncertainty budget stored in the audit trail.
Can the XS Micro Balance be integrated into a fully automated lab workflow?
When paired with LabX and optional Ethernet/Bluetooth modules, it supports unattended operation via script-driven commands, barcode-triggered weighings, and direct data push to ELN or LIMS platforms.
Is routine preventive maintenance required beyond daily calibration?
No scheduled PM is mandated; however, annual verification by an ISO/IEC 17025-accredited service provider is recommended for GxP environments to confirm linearity, eccentricity, and sensitivity drift against primary standards.
How does the XS handle electrostatic interference during microgram-scale weighing?
The draft shield incorporates grounded conductive polymer layers, and the balance firmware applies dynamic zero-tracking compensation to mitigate charge-induced drift — verified per IEC 61326-1 Annex A.3 for EMC robustness.
