Ontech Ontech 825 Dual-Channel Programmable Time-Integrated Air Sampler

Overview

The Ontech Ontech 825 Dual-Channel Programmable Time-Integrated Air Sampler is an engineered solution for regulatory-grade ambient and source-related volatile organic compound (VOC) sampling in compliance with HJ 759–2023, US EPA Methods TO-14A and TO-15, and ASTM D5466. It operates on the principle of time-integrated, constant-flow vacuum extraction—maintaining precise isothermal and isokinetic conditions during sample collection into electropolished stainless-steel or silanized SUMMA® canisters. Unlike single-point grab samplers, the Ontech 825 enables programmable multi-hour integration (1–48 h), eliminating manual intervention and reducing analytical uncertainty associated with flow drift or pressure fluctuation. Its dual-path architecture supports parallel sampling (e.g., primary + backup canister, or two distinct locations), while its integrated electronic mass flow controller—calibrated against NIST-traceable standards—ensures metrological integrity across variable backpressures up to 25 kPa.

Key Features

• Dual independent sampling channels with synchronized or asynchronous programming, each equipped with real-time flow monitoring and auto-compensation algorithms.
• Wide-range electronic flow control (10 mL/min – 2 L/min) without mechanical orifice swapping—enabling seamless transition between low-flow odorant profiling and high-flow ambient screening.
• Pre-sampling automated leak verification: applies controlled vacuum ramp, monitors pressure decay rate per ASTM D6196, and flags failures before sample draw initiation.
• Fused silica-lined flow path with deactivation via dimethyldichlorosilane vapor-phase treatment—minimizing surface adsorption of polar VOCs (e.g., formaldehyde, acetaldehyde) and reactive sulfur compounds.
• Embedded environmental sensor suite: measures and logs inlet temperature (±0.5 °C), static pressure (±0.1 kPa), and relative humidity (±3% RH) alongside flow and vacuum data.
• IP54-rated enclosure with integrated hydrophobic particulate filter (0.3 µm pore size) and desiccant cartridge—validated for continuous outdoor deployment under rain, dust, and temperature extremes (−10 °C to +50 °C).
• Rechargeable lithium-ion battery pack delivering ≥12 hours of uninterrupted operation at 500 mL/min against 20 kPa system resistance; supports hot-swap battery replacement during extended campaigns.

Sample Compatibility & Compliance

The Ontech 825 interfaces natively with industry-standard sampling media including 6 L, 1 L, and 0.5 L SUMMA®-treated stainless-steel canisters (SilcoCan®, Entech), 10–30 L fluorinated ethylene propylene (FEP) Tedlar® bags, and thermal desorption tubes (e.g., Tenax TA, Carbopack™ B/C). All wetted surfaces comply with EPA-recommended inertization protocols. The instrument’s firmware embeds method-specific logic for TO-14A (ambient air), TO-15 (source emissions), and HJ 759–2023 (China’s national ambient VOC monitoring standard), including mandatory pre- and post-sampling calibration checks, pressure stabilization thresholds, and minimum fill-volume validation. Audit trails—including operator ID, GPS-tagged location (via paired smartphone), and full parameter history—are stored in CSV/SQLite format meeting GLP/GMP metadata requirements per FDA 21 CFR Part 11 when used with optional 4G module and cloud-synced software.

Software & Data Management

Local configuration and real-time supervision are performed via the Ontech FieldLink™ mobile application (iOS/Android), which connects via Bluetooth 5.0 using secure BLE pairing—no PIN required. The app provides live flow-pressure graphs, leak-test diagnostics, and one-tap method loading (TO-15 default, custom profiles). For laboratory integration, the Ontech Desktop Suite (Windows/macOS) enables batch download of encrypted .ontx files containing raw sensor logs, calibration certificates, and QC flag annotations. All exported datasets include ISO 8601 timestamps, UTC synchronization support, and embedded digital signatures for chain-of-custody documentation. Optional 4G LTE connectivity enables remote firmware updates, scheduled job dispatching, and SMS/email alerts upon sampling completion or fault detection.

Applications

• Ambient air quality monitoring networks requiring long-term, unattended VOC speciation (e.g., ozone precursor tracking, benzene/toluene/ethylbenzene/xylene (BTEX) quantification).
• Fenceline and perimeter monitoring at petrochemical facilities, landfills, and wastewater treatment plants per EPA OTM-33 and China’s HJ 1230–2021.
• Mobile monitoring campaigns using vehicle-mounted configurations with GPS-georeferenced sampling events.
• Emergency response deployments where rapid setup, battery autonomy, and ruggedized portability are critical (e.g., chemical spill investigations, industrial fire plume characterization).
• Method validation studies supporting laboratory accreditation (ISO/IEC 17025) and regulatory submission packages for SIPs (State Implementation Plans) or EIA reports.

FAQ

Does the Ontech 825 meet US EPA Method TO-15 requirements for canister-based VOC sampling?
Yes—the instrument satisfies all instrumental performance criteria in TO-15 Section 6.2, including flow accuracy (±2%), stability (≤±2% over duration), leak-check sensitivity (<0.5 psi/min decay), and data logging resolution (1 Hz minimum).
Can it be used with non-SUMMA canisters such as SilcoNert®-treated or glass-lined containers?
Yes—provided the inlet fitting matches standard 1/4″ Swagelok® or 1/8″ NPT threads and internal passivation meets EPA-recommended inertness specifications.
Is the internal battery replaceable in the field without tools?
Yes—the battery compartment features a quick-release latch; certified replacement packs are available with CE/UL certification and 500-cycle lifecycle rating.
How is calibration traceability maintained?
Each unit ships with a factory calibration certificate traceable to NIST SRM 2715a (gas flow standard); users may perform field verification using a primary piston prover or dry calibrator compliant with ISO 6145-2.
What cybersecurity safeguards apply to the 4G remote module?
The LTE interface uses TLS 1.2 encryption for data transmission, enforces certificate-based authentication, and disables unused ports by default—aligned with IEC 62443-3-3 SL2 requirements for industrial IoT devices.