Derenda MWS-2 Manual Constant Temperature & Humidity Weighing System
| Brand | Derenda |
|---|---|
| Origin | Jiangsu, China |
| Model | MWS-2 |
| Measurement Method | Filter Gravimetric Method |
| Measured Parameters | TSP / PM₁₀ / PM₂.₅ / PM₁ |
| Compliance | HJ 836–2017, HJ 656–2013, EN 12341:2014, US EPA 40 CFR Part 86/1065, EPA QA Document No. 2.12 (Ambient Air Quality) |
| Sample Capacity (per batch) | 80 × 47 mm filters (160 with optional storage tower), 30 × 90 mm filters (60 with tower), 24 × low-concentration samplers (48 with tower), 24 × No.3 impinger tubes (48 with tower) |
| Temperature Control Range | 15–30 °C (±0.1 °C stability) |
| Humidity Control Range | 40–55 %RH (±2 %RH accuracy) |
| Dew Point Stability | ±0.1 °C |
| Chamber Cleanliness | ISO 14644 Class 6 |
| Weighing Instrument Options | Analytical balance with readability down to 0.01 mg (10 µg) or 0.001 mg (1 µg), integrated anti-vibration platform with decoupling architecture |
| Electrostatic Neutralization | Ionizing air blower (radiation-free, 100% neutralization efficiency per cycle) |
| Identification | QR code, barcode, and optional RFID encoding (chip embedded in sample holder ring) |
| User Interface | Ergonomic front access ports, large transparent viewing panel, built-in control software with audit-trail-capable database |
| Power | 220 V ±10%, 50 Hz, 1000 W |
| Dimensions | 1180 mm (L) × 800 mm (W) × 2000 mm (H) |
| Weight | 400 kg (including climate module) |
Overview
The Derenda MWS-2 Manual Constant Temperature & Humidity Weighing System is a precision-engineered gravimetric platform designed for standardized mass determination of atmospheric particulate matter collected on filter media. It operates in strict accordance with the fundamental principle of filter-based gravimetric analysis—measuring the mass difference of a pre- and post-sampling filter under rigorously controlled environmental conditions—to quantify ambient aerosol concentrations (TSP, PM10, PM2.5, and PM1). Unlike conventional laboratory balances used in uncontrolled environments, the MWS-2 integrates a fully sealed, ISO Class 6 clean chamber with active temperature and humidity regulation (15–30 °C ±0.1 °C; 40–55 %RH ±2 %RH), eliminating hygroscopic bias and thermal drift that compromise measurement integrity. Its architecture supports manual handling workflows while enforcing metrological traceability through automated environmental logging, RFID-enabled sample tracking (optional), and full data audit trails—making it suitable for laboratories operating under GLP, ISO/IEC 17025, or regulatory-compliant ambient monitoring programs.
Key Features
- Sealed ISO 14644 Class 6 weighing chamber with integrated FFU (Fan Filter Unit) providing continuous HEPA-filtered laminar airflow
- High-stability climate control system eliminating need for dedicated HVAC infrastructure or external walk-in chambers
- Front-access pull-out sample loading bay—enabling filter insertion and retrieval without opening the main chamber door, minimizing environmental perturbation
- Modular sample staging: independent holders for 47 mm and 90 mm filters, low-concentration samplers, and No.3 impinger tubes—with scalable capacity via optional dual-tier storage towers
- RFID-enabled sample identification (optional): chip-embedded sample rings enable automatic registration, chain-of-custody logging, and error-resistant workflow management
- Ionizing electrostatic neutralization system delivering 100% surface charge removal per exposure cycle—critical for accurate microgram-level weighing of hydrophobic or synthetic membranes
- Dual-isolation anti-vibration design: mechanically decoupled analytical balance platform combined with internal damping structure to suppress microseismic and acoustic interference
- Ergonomic workstation layout featuring anthropometric hand ports, wide-angle optical viewport, and intuitive touchscreen interface
- Future-ready architecture:预留 modular interfaces for seamless integration of robotic sample handlers and automated balance actuators—facilitating upgrade to semi- or fully-automated operation
Sample Compatibility & Compliance
The MWS-2 accommodates a broad range of standard and method-specific sampling media, including quartz fiber, PTFE, cellulose ester, and nylon membrane filters (47 mm and 90 mm diameters), as well as low-concentration aerosol samplers and EPA-compliant No.3 impinger tubes. All configurations maintain uniform environmental exposure across samples during equilibration—ensuring consistent moisture adsorption/desorption kinetics prior to weighing. The system meets or exceeds requirements outlined in key regulatory frameworks: Chinese national standards HJ 836–2017 (determination of particulate matter in stationary source emissions) and HJ 656–2013 (ambient PM2.5 monitoring); European standard EN 12341:2014 (ambient air quality—measurement of PM10/PM2.5); U.S. EPA methods 40 CFR Part 86 (vehicle emissions) and Part 1065 (engine testing), and the EPA’s Quality Assurance Document No. 2.12 for ambient air monitoring networks. Environmental logs—including timestamped temperature, humidity, dew point, and chamber pressure—are automatically archived with each weighing event, supporting FDA 21 CFR Part 11–compliant electronic records when paired with validated software configuration.
Software & Data Management
The embedded control software provides real-time monitoring of chamber conditions, balance status, and user activity. Each weighing session generates a structured metadata record containing operator ID, sample ID (QR/barcode/RFID), environmental parameters at t0 and tf, balance calibration history, and raw mass values with uncertainty estimates. All data are stored in an encrypted local SQL database with configurable retention policies and export capability to CSV, PDF, or LIMS-compatible XML formats. Audit trail functionality captures all modifications—including edits to sample annotations or environmental setpoints—with immutable timestamps and user attribution. Optional software validation packages support IQ/OQ documentation and compliance with ISO/IEC 17025 Clause 7.7 (result reporting) and GLP Principle 5 (data integrity).
Applications
- Ambient air quality monitoring networks requiring gravimetric PM1, PM2.5, PM10, and TSP quantification per national or international protocols
- Source emission testing laboratories performing stack sampling analysis under HJ 836–2017 or EPA Method 5/17
- Research institutions conducting aerosol hygroscopicity, volatility, or composition studies where precise dry mass is foundational
- Calibration and reference labs maintaining traceable mass standards for filter-based instrumentation
- Environmental consultancies performing third-party verification of compliance monitoring data
FAQ
What environmental standards does the MWS-2 satisfy for regulatory reporting?
The system fulfills technical requirements of HJ 836–2017, HJ 656–2013, EN 12341:2014, and US EPA QA/QC guidance documents for ambient and source testing—particularly regarding temperature/humidity stability, cleanliness class, and data traceability.
Can the MWS-2 be integrated into an existing LIMS environment?
Yes—via configurable API endpoints and standardized data export formats (CSV, XML), enabling bidirectional synchronization with most modern LIMS platforms.
Is the ionizing neutralizer safe for routine use in occupied laboratories?
Yes—the device employs low-energy corona discharge technology with no radioactive isotopes or ozone generation, complying with IEC 61340-5-1 for electrostatic protection in controlled environments.
How is measurement uncertainty managed across multiple operators?
Through standardized SOP enforcement via software-guided workflows, mandatory environmental stabilization checks before weighing, and operator-authenticated digital signatures on every result entry.
What maintenance intervals are recommended for long-term metrological reliability?
Annual calibration of climate sensors and balance against NIST-traceable references is advised; FFU filter replacement every 12 months (or per manufacturer’s particle load assessment); ionizer emitter cleaning every 6 months.
