PWC254 Precision Analytical Balance with Internal Calibration – 250 g / 0.1 mg (UK-Sourced)
| Origin | United Kingdom |
|---|---|
| Model | PWC254 |
| Maximum Capacity | 250 g |
| Readability | 0.1 mg |
| Repeatability | ±0.2 mg |
| Linearity Error | ±0.2 mg |
| Pan Diameter | 90 mm |
| Operating Temperature | 10–40 °C |
| Power Supply | 100–240 V AC, 50/60 Hz, 15 V DC output |
| Interface | RS-232 bidirectional |
| Display | Dual-line backlit LCD with range tracking |
| Draft Shield Dimensions | 202 × 158 × 215 mm |
| Housing | Die-cast aluminum with transparent glass draft shield |
| External Dimensions | 256 × 524 × 275 mm |
| Net Weight | 12 kg |
Overview
The PWC254 Precision Analytical Balance is a UK-sourced, high-reliability laboratory balance engineered for routine and regulated analytical weighing tasks requiring resolution to 0.1 mg (100 µg). Built on electromagnetic force restoration (EMFR) sensor technology, it delivers stable, drift-compensated measurements under variable ambient conditions. Its internal calibration mechanism—activated automatically or manually—compensates for thermal drift and temporal sensor drift without requiring external weights, ensuring traceable accuracy across shifts and extended operational cycles. Designed for ISO/IEC 17025-compliant laboratories, the PWC254 meets fundamental metrological requirements for Class I analytical balances per OIML R 76-1 and ASTM E898-22. The die-cast aluminum chassis and sealed optical sensor assembly provide mechanical robustness and resistance to vibration-induced noise, while the integrated glass draft shield minimizes convective air currents during low-mass measurements.
Key Features
- Internal motorized calibration system with temperature-triggered and time-scheduled activation—no manual weight handling required
- Dual-line backlit LCD display with real-time range tracking: visual indication of remaining capacity relative to current tare load
- Full-range tare functionality with automatic zero-tracking and auto-zero stabilization
- RS-232 serial interface compliant with standard PC and thermal printer protocols; supports ASCII and MODBUS RTU framing
- User-accessible password protection (4-digit PIN) for configuration lockout and function restriction
- Integrated statistical functions: mean, standard deviation, coefficient of variation, and count-based repeatability assessment
- Multi-mode weighing: percentage weighing, parts counting, density determination (solid/liquid), animal/dynamic weighing, and custom unit definition
- Configurable alarm thresholds for upper/lower limit checking—ideal for QC pass/fail workflows
Sample Compatibility & Compliance
The PWC254 accommodates standard laboratory sample containers—including crucibles, weighing boats, and volumetric flasks—on its 90 mm diameter stainless steel pan. Its draft shield (202 × 158 × 215 mm) conforms to ISO 9001 and GLP environmental control guidelines for static weighing environments. The balance is suitable for use in GMP-regulated settings where audit trails and operator accountability are required; though it does not natively support FDA 21 CFR Part 11 electronic signatures, its RS-232 output enables integration with validated LIMS or ELN platforms that provide full electronic record integrity. Calibration certificates issued by UKAS-accredited providers are available upon request, supporting traceability to NPL (National Physical Laboratory) standards.
Software & Data Management
Data export is supported via ASCII-formatted RS-232 transmission at configurable baud rates (9600–115200 bps), compatible with Windows-based data acquisition software, Excel automation scripts, and industry-standard laboratory informatics systems. The balance stores up to 99 user-defined weighing protocols—including tare sequences, unit conversions, and alarm presets—in non-volatile memory. All parameter changes—including calibration history timestamps, password modifications, and mode selections—are logged internally with date/time stamps. While no embedded database or touchscreen GUI is included, firmware updates are delivered via serial command protocol and verified using CRC-16 checksums to ensure integrity.
Applications
- Pharmaceutical formulation: active pharmaceutical ingredient (API) dispensing, excipient ratio verification, and batch release testing per USP <41>
- Materials science: catalyst mass dosing, thin-film deposition precursor quantification, and nanomaterial dispersion preparation
- Environmental testing: filter weighing for PM2.5/PM10 analysis, soil moisture content determination, and gravimetric VOC recovery validation
- Academic research: stoichiometric reagent preparation, polymer synthesis yield calculation, and electrochemical electrode loading quantification
- Quality control labs: incoming raw material verification, finished product net weight compliance, and packaging line checkweighing support
FAQ
Does the PWC254 support external calibration with certified weights?
Yes—the balance accepts manual external calibration using Class E2 or better stainless steel weights traceable to national standards. Internal calibration remains active unless explicitly disabled.
Is the RS-232 interface optically isolated?
No—it is electrically isolated via onboard transient voltage suppression but lacks galvanic isolation. For high-noise industrial environments, a USB-to-RS-232 converter with isolation is recommended.
Can the balance be operated on battery power?
No—the unit requires continuous 15 V DC input from its included switching power adapter; no internal or optional battery module is available.
What is the warm-up time to achieve specified repeatability?
Minimum 30 minutes after power-on at 23 ± 2 °C ambient; full metrological stability is reached within 60 minutes under steady-state conditions.
Are firmware updates field-installable?
Yes—updates are distributed as binary files and applied via terminal command sequence over RS-232; technical documentation includes version-controlled release notes and rollback procedures.
