QC-2B Dual-Channel Independent-Timing Air Sampler

Overview

The QC-2B Dual-Channel Independent-Timing Air Sampler is a portable, microprocessor-controlled sampling instrument engineered for simultaneous collection of two discrete gaseous samples under individually programmable time intervals. It operates on the principle of constant-flow aspiration via two electrically isolated diaphragm vacuum pumps, each driving a dedicated sampling path with independent timing control. This architecture eliminates cross-channel interference and enables parallel sampling of different analytes—such as sulfur dioxide (SO₂) and nitrogen oxides (NOₓ)—or duplicate sampling for statistical validation in accordance with EPA Method IO-2.1, ISO 16000-23, and occupational hygiene standards including NIOSH Method 6004 and OSHA ID-121. Designed for field deployment in ambient air quality monitoring and workplace exposure assessment, the QC-2B maintains flow stability and timing fidelity across variable backpressure conditions generated by sorbent tubes, impingers, or filter cassettes.

Key Features

• Dual independent sampling channels, each equipped with a calibrated diaphragm pump and dedicated digital timer (1–99 min range, factory-defaulted to 30 min)
• Adjustable flow rate from 0.1 to 1.5 L/min per channel, continuously monitored and stabilized via integrated feedback circuitry
• Flow accuracy ±5% and stability ≤5% over full operating temperature range (−10 to 40 °C), verified per ISO 9001 calibration protocols
• Timing accuracy <0.1%, traceable to internal quartz oscillator with temperature compensation
• Compact ergonomic housing (210 × 125 × 95 mm) constructed from impact-resistant ABS polymer with IP54-rated ingress protection
• Rechargeable Ni-MH battery pack supporting >6 hours of continuous dual-channel operation at 1.0 L/min flow
• Low-noise operation (<55 dB(A) at 1 m), suitable for indoor and mobile monitoring applications

Sample Compatibility & Compliance

The QC-2B interfaces seamlessly with standard 10–40 mm diameter absorption bottles (e.g., silica gel, activated carbon, or impinger-based collection media), glass fiber filters, and solid sorbent tubes (e.g., SKC Ultra, Anasorb). Its dual-path design supports co-sampling strategies required by EN 13725 (odor measurement), ISO 16017-1 (VOCs in workplace air), and Chinese HJ/T 375–2007 (ambient air sampling methodology). All electronic components comply with IEC 61000-4 electromagnetic compatibility standards; the device meets GB/T 18204.1–2013 (Chinese national standard for air sampler performance) and is CE-marked for use in non-explosive environments. While not intrinsically safe, it may be deployed in Zone 2/Class I, Division 2 areas when used with external explosion-proof enclosures per ATEX Directive 2014/34/EU guidance.

Software & Data Management

The QC-2B operates autonomously without PC connectivity; however, its embedded timer module logs start/stop timestamps, total elapsed sampling time, and average flow rate per channel into non-volatile memory (100-event capacity). Data export is supported via optional USB-C adapter (sold separately), enabling CSV-formatted download compatible with LIMS platforms and regulatory reporting tools. Audit trails include operator ID input (via front-panel keypad), calibration date stamping, and firmware version tracking—facilitating GLP-compliant documentation under ISO/IEC 17025 laboratory accreditation requirements. Firmware updates are delivered via secure encrypted binary files validated through SHA-256 checksum verification.

Applications

• Ambient air quality monitoring networks (PM₂.₅ precursor gases, ozone precursors, VOC speciation)
• Workplace exposure assessment for regulated contaminants (e.g., formaldehyde, benzene, hydrogen sulfide) per OELs defined in ACGIH TLVs® and EU Directive 2017/2398
• Indoor air quality surveys in commercial buildings, schools, and healthcare facilities
• Stack emission pre-screening and fugitive emission source identification
• Method validation studies requiring paired-sample collection under identical environmental conditions
• Field training and proficiency testing for environmental health and safety personnel

FAQ

Can the QC-2B operate both channels at different flow rates simultaneously?
Yes—each channel features independent flow adjustment via precision needle valves and real-time digital readout, allowing asymmetric sampling configurations.
Is battery life affected when operating at maximum flow (1.5 L/min)?
At 1.5 L/min per channel, runtime reduces to approximately 4.2 hours due to increased power draw; nominal 6-hour rating applies at 1.0 L/min.
Does the instrument support external trigger inputs or remote start/stop?
No—the QC-2B lacks RS-232, Bluetooth, or dry-contact interfaces; all control is local via membrane keypad and LED display.
What calibration standards are recommended for annual verification?
Primary calibration should be performed using a NIST-traceable primary standard flowmeter (e.g., Brooks 5850E or Mesa Labs DryCal DC-Lite) per ISO 6145-4 guidelines.
Are spare parts and service support available outside mainland China?
Yes—authorized regional service centers in Southeast Asia, the Middle East, and Latin America provide technical support, firmware updates, and certified replacement pumps and timers.