YINHEKEJI TWA-300H Low-Flow Air Sampler

Overview

The YINHEKEJI TWA-300H Low-Flow Air Sampler is a portable, single-channel active sampling instrument engineered for precision time-weighted average (TWA) and short-term exposure limit (STEL) air monitoring in occupational hygiene and environmental assessment applications. It operates on the principle of controlled volumetric aspiration—drawing ambient air through sorbent tubes (e.g., activated carbon, silica gel) or impingers at precisely regulated low flow rates (20–500 mL/min), ensuring quantitative collection of gaseous and vapor-phase contaminants without breakthrough or channeling. Its high-vacuum capability (>26 kPa) enables reliable sampling even against elevated backpressure from densely packed sorbent media or long sampling lines—critical for compliance with ISO 16000-6, NIOSH methods (e.g., 1501, 1502), and OSHA ID-142. Designed for both personal (belt-mounted) and area (fixed-location) monitoring, the TWA-300H supports full-shift (up to 8 h) or segmented sampling protocols required for regulatory reporting under EU Directive 2004/37/EC (CARC) and ACGIH TLV® guidelines.

Key Features

• Single-channel architecture optimized for low-flow sorbent tube sampling—minimizes cross-contamination risk and simplifies calibration traceability
• High-efficiency brushless DC motor with thermal overload protection ensures stable performance across temperature extremes (–5 to 50 °C)
• Integrated digital timer with 0.1% timing accuracy; programmable duration from 1 min to 99 h 59 min, supporting multi-stage exposure assessments
• Dual power operation: mains-powered (220 V AC) for lab or fixed-site use; field-deployable with rechargeable 7.4 V Li-ion battery pack (≥12 h runtime at 100 mL/min)
• Real-time low-battery warning: all four display digits flash synchronously when voltage drops below operational threshold
• Compact, lightweight design (≤0.5 kg, 137 × 88 × 45 mm) meets ISO 9001 ergonomic requirements for extended wear during personal monitoring
• Robust housing with IP54-rated ingress protection against dust and incidental water splashes during field deployment

Sample Compatibility & Compliance

The TWA-300H is validated for use with standard 3.5–4.0 cm × 60–90 mm sorbent tubes—including charcoal (NIOSH 501, 504), silica gel (NIOSH 502, 504), and mixed-bed configurations—as well as impinger-based liquid absorption (e.g., formaldehyde in DNPH solution per EPA TO-11A). Its flow stability (≤±5% over 1 h) and metering accuracy (≥±2.5% FS) align with ISO 13137:2013 requirements for personal sampling pumps. The instrument’s flow calibration protocol supports traceable adjustment using primary standards (e.g., bubble meters, electronic calibrators per ISO 5725), enabling audit-ready documentation for GLP-compliant laboratories and OSHA-mandated exposure records. All internal wetted materials are chemically inert (FDA-compliant PTFE and polypropylene), preventing analyte adsorption or catalytic degradation.

Software & Data Management

The TWA-300H operates as a standalone hardware platform without proprietary software dependencies—ensuring compatibility with industry-standard data acquisition systems (e.g., LabVIEW, MATLAB) via optional RS-232 or analog output modules (available as accessories). All sampling parameters—including start time, set flow rate, elapsed duration, and battery status—are logged internally and displayed in real time on the 4-digit LCD. For regulatory reporting, users export raw field data manually into validated spreadsheets compliant with 21 CFR Part 11 (when paired with controlled electronic records procedures) or ISO/IEC 17025 documentation workflows. Firmware updates (if released) are performed via USB interface with cryptographic signature verification to maintain integrity.

Applications

• Occupational exposure assessment for VOCs (benzene, toluene, xylene), aldehydes (formaldehyde, acetaldehyde), and inorganic gases (NO₂, SO₂, H₂S) per NIOSH, OSHA, and EN 13205
• Indoor air quality (IAQ) surveys in offices, schools, and healthcare facilities under ISO 16000 series protocols
• Baseline environmental monitoring near industrial emission sources or remediation sites
• Validation of engineering controls (e.g., local exhaust ventilation efficiency) through pre- and post-intervention sampling
• Research-grade vapor-phase partitioning studies requiring precise, low-flow kinetic sampling

FAQ

What sorbent tubes are compatible with the TWA-300H?
Standard 60–90 mm × 4 mm OD glass or stainless-steel sorbent tubes—including activated carbon (ASTM D5209), silica gel (ISO 16017-2), and Tenax TA—are fully supported. Tube resistance must remain below 26 kPa at selected flow rates.

Can the TWA-300H be used for continuous 8-hour TWA sampling?
Yes. With pre-charged batteries and flow set between 50–200 mL/min, it maintains ≤±5% flow deviation over 8 h—meeting NIOSH and ISO 13137 criteria for full-shift monitoring.

Is calibration traceable to national standards?
Yes. Flow calibration uses certified reference instruments (e.g., dry calibrators per ISO 5725) and is documented per ISO/IEC 17025 requirements. Calibration certificates include uncertainty budgets and environmental correction factors.

Does the device support remote monitoring or data logging?
As a dedicated sampling pump, it does not include built-in memory or wireless telemetry. However, analog output (0–5 V) and RS-232 interfaces enable integration with external dataloggers compliant with IEC 61508 SIL-2.

What maintenance is required to sustain ≥5000 h service life?
Annual inspection of motor brushes (if applicable), filter replacement every 200 h of operation, and biannual flow verification using a primary standard. No lubrication or internal disassembly is required under normal use.