Tianhong TH-J3 Portable Flow Calibration Standard for Flue Gas and Particulate Samplers

Overview

The Tianhong TH-J3 Portable Flow Calibration Standard is a metrologically traceable, field-deployable calibration instrument engineered specifically for the periodic verification of volumetric flow rates in environmental flue gas and particulate sampling systems. It operates on the principle of critical orifice flow measurement under controlled pressure differentials—leveraging calibrated orifice plates and real-time compensation for local atmospheric pressure and ambient temperature to deliver accurate, repeatable flow rate determinations across its operational range. Designed in strict accordance with JJG 577–2005 (the People’s Republic of China National Verification Regulation for Diaphragm Gas Meters) and the enterprise standard Q/WTH42–2013, the TH-J3 ensures traceability to national metrological standards and supports compliance with ISO/IEC 17025–2017 requirements for calibration laboratories performing field verifications. Its primary application domain includes quality assurance workflows in environmental monitoring stations, third-party testing laboratories, and industrial emission compliance units where regulatory-grade validation of stack samplers, isokinetic samplers, and low-flow particulate collectors is mandated.

Key Features

• Field-portable architecture: Compact footprint and lightweight construction (< 3.5 kg) enable single-operator deployment in remote stack access points, mobile lab vans, and outdoor monitoring sites.
• Integrated environmental sensing: Onboard high-accuracy digital barometer and thermistor provide real-time P_atm and T_amb inputs—automatically applied to flow calculations per ISO 5167–2 and ASTM D6348–22 correction protocols.
• Microprocessor-controlled operation: Embedded ARM-based controller executes automated flow stabilization routines, dwell-time sequencing, and linear regression analysis of differential pressure vs. flow output.
• Human-centered interface: 128×64 pixel monochrome OLED display with native Chinese character rendering; intuitive touch-sensitive membrane keypad with context-aware prompts reduces operator training burden and minimizes input errors.
• Self-contained power system: Industrial-grade lithium-ion battery pack delivers ≥20 hours of continuous operation at 25°C—certified to IEC 62133 for safe transport and extended field use without AC dependency.
• On-device documentation: Integrated thermal printer outputs time-stamped calibration reports including date/time stamp, ambient conditions, measured flow rate, uncertainty budget components, and operator ID field—supporting GLP audit readiness.

Sample Compatibility & Compliance

The TH-J3 is validated for calibration of flow sensors and sampling pumps used in EPA Method 5, ISO 9096, HJ/T 48–1999 (Chinese standard for particulate matter sampling), and GB/T 16157–1996 (determination of flue gas flow velocity). It accommodates nominal inlet diameters from 6 mm to 25 mm and supports flow ranges typical of low-flow (< 20 L/min) and medium-flow (20–100 L/min) environmental samplers. All internal orifices are individually calibrated by an accredited metrology institute against NIM (National Institute of Metrology, China) reference standards, with calibration certificates issued per ISO/IEC 17025. The device itself bears a valid CNAS-accredited verification mark and conforms to electromagnetic compatibility requirements outlined in GB/T 18268.31–2017 (IEC 61326–2–2).

Software & Data Management

While the TH-J3 operates as a standalone field instrument, its internal firmware supports USB-C data export in CSV format for post-processing in laboratory information management systems (LIMS) or statistical analysis platforms (e.g., Minitab, JMP). Each stored record contains: timestamp (YYYY-MM-DD HH:MM:SS), measured volumetric flow (L/min), static pressure (kPa), ambient temperature (°C), battery voltage (V), and pass/fail flag based on user-defined tolerance thresholds (±2% FS typical). Audit trails—including parameter changes, calibration due dates, and firmware version—are retained in non-volatile memory and accessible via service mode. Data integrity complies with basic ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate), though full 21 CFR Part 11 electronic signature functionality requires external LIMS integration.

Applications

• Periodic field verification of isokinetic samplers prior to stack testing campaigns (per EPA SW-846 Method 0030).
• Pre- and post-maintenance calibration checks of diaphragm pumps in PM_2.5/PM₁₀ ambient air samplers (e.g., TEOM, beta attenuation monitors).
• Traceable flow adjustment of dilution tunnels used in vehicle exhaust emission testing facilities.
• Validation of flow controllers in continuous emission monitoring systems (CEMS) during site acceptance tests (SAT).
• Training and proficiency testing for environmental technicians under CNAS accreditation requirements.

FAQ

What flow rate range does the TH-J3 support?
The TH-J3 is configured for nominal flow verification between 5 L/min and 100 L/min, optimized for environmental sampling applications requiring ±2% full-scale accuracy under compensated conditions.
Is the TH-J3 suitable for calibrating mass flow controllers (MFCs)?
No—it is designed exclusively for volumetric flow calibration of gas displacement devices (e.g., dry gas meters, diaphragm pumps, rotameters) and does not compensate for gas composition or molecular weight variations inherent to thermal MFCs.
How often must the TH-J3 itself be recalibrated?
Per Q/WTH42–2013, the unit requires annual verification by an accredited metrology laboratory; internal diagnostics and drift checks are recommended before each field campaign.
Can the TH-J3 operate in explosive atmospheres?
It is not intrinsically safe (non-ATEX/IECEx certified) and must not be deployed in Zone 0/1 hazardous areas without secondary containment or purging systems.
Does the TH-J3 meet international metrological traceability requirements?
Yes—its orifice calibration certificates are issued by CNAS-accredited labs with direct traceability to NIM’s primary standards, satisfying ISO/IEC 17025 clause 6.6 and EU Measurement Instruments Directive (MID) Annex MI-002 equivalency pathways.