Tianhong TH-110H Constant-Temperature Ambient Air Sampler

Overview

The Tianhong TH-110H Constant-Temperature Ambient Air Sampler is an intelligent, microprocessor-controlled environmental monitoring instrument engineered for regulatory-grade 24-hour continuous ambient air sampling in compliance with Chinese national standards HJ/T 375–2007, HJ/T 376–2007, and JJG 956–2013. Designed for high-reliability operation under variable field conditions, the TH-110H employs semiconductor-based thermoelectric cooling and heating to maintain sample gas temperature precisely at 24 ± 2 °C—critical for preserving volatile organic compound (VOC) integrity and ensuring metrological consistency across seasonal ambient fluctuations. Unlike passive or ambient-temperature samplers, the TH-110H actively regulates thermal conditions within its integrated sampling chamber, preventing condensation-induced analyte loss or ice formation in cold climates—a known source of bias in PM_2.5, formaldehyde, ozone precursor, and carbonyl compound measurements. Its single-channel architecture supports gravimetric, sorbent-tube, and impinger-based collection methods, making it suitable for fixed-site monitoring stations, mobile laboratories, and short-term field campaigns where trace-level reproducibility and long-duration stability are required.

Key Features

• Semiconductor temperature control system ensures stable 24 ± 2 °C operation independent of ambient conditions—eliminating cold-weather sampling failure due to freezing in desiccant or absorption bottles.
• Integrated dual-bottle housing (sampling + drying) fully enclosed within instrument chassis—reducing exposure to external thermal gradients and mechanical vibration.
• Microprocessor-driven flow regulation with real-time digital feedback loop enables automatic constant-flow operation across variable backpressure conditions typical of filter loading or sorbent breakthrough.
• 4.3-inch high-brightness color touchscreen interface provides intuitive navigation, parameter configuration, and live status visualization—including real-time flow rate, temperature, atmospheric pressure, and pre-flow pressure.
• Onboard environmental sensor suite automatically measures and logs ambient temperature, barometric pressure, and inlet pressure—enabling dynamic correction of volumetric flow to standard reference conditions (e.g., 25 °C, 101.325 kPa).
• Non-volatile memory retains all operational parameters and sampling records (>500 entries per channel) during power interruption; resumes sampling automatically upon power restoration without data loss.
• Imported brushless diaphragm pump delivers low acoustic emission (<55 dB(A)), extended service life, and consistent vacuum performance under sustained load.
• Software-based calibration capability allows field-adjustment of flow, temperature, and pressure transducers via touchscreen—reducing dependency on external metrology labs for routine verification.

Sample Compatibility & Compliance

The TH-110H supports a broad range of EPA- and ISO-aligned sampling media, including quartz fiber filters (PM₁₀/PM_2.5 gravimetry), polyurethane foam (PUF) and XAD-2 resin cartridges (for semi-volatile organics), silica gel tubes (for aldehydes), and bubblers containing absorbing solutions (e.g., DNPH for carbonyls). Its design conforms to the physical and thermal requirements specified in HJ/T 376–2007 for 24-hour continuous samplers, particularly regarding temperature uniformity, flow stability under resistance variation, and data traceability. While not certified to ISO/IEC 17025 or US EPA Compendium Method TO-17 out-of-the-box, the instrument’s programmable logging, audit-ready timestamping, and parameter-locking functionality support GLP-compliant workflows when paired with documented SOPs and external calibration certificates.

Software & Data Management

Data acquisition and management are handled by embedded firmware compliant with Q/WTH24–2016 (enterprise standard for TH-110F/H series). All sampling events—including start/stop time, setpoint vs. actual flow, temperature deviation, pressure drop, and cumulative volume (both as-is and normalized to reference conditions)—are stored with millisecond-resolution timestamps. Data export is supported via USB mass storage mode (CSV format) or optional cellular telemetry module, enabling secure transmission of instrument status, GPS coordinates, and historical records to centralized environmental data platforms. The firmware includes configurable password protection for critical settings, user-defined sampling schedules, and editable metadata fields (site ID, analyst code, method ID), facilitating integration into LIMS environments. Audit trail functionality meets baseline requirements for internal quality assurance; full 21 CFR Part 11 compliance requires supplemental validation and electronic signature implementation by end users.

Applications

The TH-110H serves core applications in regulatory air quality monitoring networks, university atmospheric chemistry research, occupational hygiene assessments, and municipal public health surveillance. It is routinely deployed for: long-term trend analysis of criteria pollutants (SO₂, NO_x, O₃) using chemiluminescence or UV photometry pre-concentration; source apportionment studies requiring speciated VOC sampling on multi-bed sorbent tubes; indoor air quality investigations involving formaldehyde and acetaldehyde quantification; and validation of low-cost sensor networks through co-located reference-grade sampling. Its compact footprint (≤380 × 220 × 260 mm) and <6 kg weight enable rooftop mounting, vehicle-integrated deployment, and rapid repositioning across urban transects—without compromising thermal or flow stability.

FAQ

Does the TH-110H support dual-channel simultaneous sampling?
No—the TH-110H is a single-channel sampler. For parallel sampling, two units must be deployed with synchronized start times.
What is the maximum allowable system resistance for stable flow control?
The instrument maintains rated flow accuracy up to 25 kPa backpressure, typical for loaded 47-mm quartz filters or 300-mm sorbent tubes.
Can the temperature setpoint be adjusted outside the 24 ± 2 °C range?
No—thermal regulation is factory-fixed to comply with HJ/T 376–2007; deviation would invalidate regulatory data acceptability.
Is remote firmware update supported over cellular connection?
Firmware updates require local USB connection; remote diagnostics and data upload are supported, but not OTA updates.
What calibration gases or reference standards are recommended for field verification?
Primary calibration should use NIST-traceable dry calibrators (e.g., DryCal DC Series) at ambient temperature and pressure; temperature verification requires a calibrated PT100 probe inserted into the sample path.