Mettler Toledo NewClassic MF, MS204s Balance

Mettler Toledo NewClassic™ MF — MS204S Analytical Balance (0.1 mg)

The Mettler Toledo NewClassic™ MS Series, represented here by the MS204S analytical balance, is a laboratory-grade precision weighing instrument designed for routine analytical work, QC testing, formulation, and research applications requiring 0.1 mg (0.0001 g) readability. The NewClassic MF designation refers to this family of robust, metal-housed analytical balances equipped with Mettler Toledo's proven electromagnetic force compensation (EMFC) MonoBloc® weighing cell and FACT® (Fully Automatic Calibration Technology)—a temperature- and time-triggered internal adjustment system that maintains calibration integrity without user intervention. With a maximum capacity of 220 g​ and 0.1 mg readability, the MS204S is classified as a semi-micro/analytical balance suitable for precise weighing of reference standards, active pharmaceutical ingredients (APIs), reagents, filters, and small-volume samples.

Weighing Technology & Accuracy

At the core of the MS204S is the MonoBloc® single-module weighing sensor, a high-precision EMFC cell manufactured from a single piece of metal to eliminate mechanical linkages and reduce sources of error. This design provides excellent repeatability (typical sd = 0.1 mg; best-case 0.05 mg), fast stabilization (≈2 s), and resistance to shock loads via built-in overload protection (up to 9× capacity on some models). The FACT® internal calibration uses a factory-installed internal test weight to perform automatic adjustment when the balance detects a temperature shift (threshold typically ±1–2 °C from last calibration) or after a user-defined time interval. This eliminates reliance on external calibration weights for day-to-day verification and supports consistent results across changing ambient conditions. Manual external calibration with user-supplied weights (100–220 g range) is also supported.

User Interface & Workflow Features

The MS204S is equipped with a High Contrast Display (HCD)—a backlit graphical LCD with oversized digits and clearly legible unit/icons—making it readable even under poor lighting or from a distance. Operation is menu-driven but simplified: three programmable SmartKeys (F1–F3)​ allow one-touch launch of frequently used applications such as piece counting, percent weighing, check weighing, formulation (net total), statistics, or density determination. A SmartTrac®​ graphic bar on-screen shows how much of the weighing range is currently occupied, helping the user avoid overload situations.

Leveling is simplified by front-mounted leveling feet and a prominent circular level indicator, plus an optional LevelControl™ warning that alerts the user if the balance has been moved out of level. The balance also includes a built-in real-time clock​ for GLP/GMP-compliant printouts showing date, time, balance ID, calibration status, and sample weight.

Draft Shield & Ergonomics

The analytical draft shield features ErgoDoors®—side-hinged glass panels that can be opened with the opposite hand (e.g., right door operated with left hand) for convenient sample placement and reduced reach. A QuickLock®​ system allows all glass panels and the top plate to be removed without tools in seconds; the separated glass parts are dishwasher-safe, promoting fast decontamination between samples. The full-metal die-cast aluminum base and housing resist common lab chemicals including acetone and ethanol, and the instrument ships with a protective cover for storage.

Built-in Applications

• Basic Weighing​ — in 16 selectable units (g, mg, kg, ct, lb, oz, ozt, dwt, GN, momme, tael, etc.)

• Piece Counting​ — with automatic optimization using a reference quantity

• Percent Weighing​ — compares sample mass to a 100 % reference

• Check Weighing​ — with configurable HI/OK/LO limits and audible alert

• Formulation / Totaling​ — accumulates net component masses; ideal for multi-ingredient recipes

• Statistics​ — mean, standard deviation, min/max, CV across multiple weighings

• Density Determination​ — of solids (via buoyancy method) or liquids (with optional density kit)

• Dynamic Weighing / Animal Weighing​ — averages unstable samples over time

• Free Factor / Division Factor​ — for non-standard unit conversions

Data Communication & Compliance

The MS204S provides:

• RS-232C serial port​ (standard) — for direct connection to printers, barcode readers, or secondary displays

• USB-B device port​ (standard) — for PC connection using Mettler Toledo LabX® direct or MT-SICS protocol

• Compatibility with LabX® light or server software​ for method management, electronic records, and audit trails (when configured for 21 CFR Part 11 environments)

• GLP/GMP-format print templates including balance ID, calibration log, date/time stamp

Minimum sample weight per USP Chapter <41> is typically ≥0.30 g​ (0.1 %, k=2 criterion gives ~0.02 g as theoretical minimum); users should perform a repeatability test to determine their own validated minimum weight.

Common Applications

• Pharmaceutical QC — API/Excipient weighing for tablet/capsule formulation, standard prep for HPLC/UV

• Biotechnology — weighing enzymes, buffers components, reference proteins

• Chemical R&D — catalyst weighing, reagent preparation for synthesis

• Food & Environmental — filter paper pre/post-weighing for suspended solids (TSS), additive quantification

• Academic — teaching labs, micro-analytical exercises

Technical Specifications — MS204S Analytical Balance

Specifications are based on Mettler Toledo NewClassic MS Series datasheets (Material No. 11124477). The MS204S has been succeeded in some markets by the MS204TS/ME models; please verify current availability with your local Mettler Toledo distributor.