TH-502 Intelligent Diesel Smoke Meter
| Origin | Hubei, China |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Origin Category | Domestic (China) |
| Model | TH-502 |
| Pricing | Upon Request |
Overview
The TH-502 Intelligent Diesel Smoke Meter is a precision-engineered optical instrument designed for quantitative measurement of diesel exhaust smoke opacity in accordance with internationally recognized principles of split-stream opacimetry. It operates on the fundamental photometric principle of light attenuation—measuring the reduction in transmitted light intensity across a defined sample path as diesel particulate matter (DPM) intercepts the beam. Unlike integrating sphere-based or filter-based methods, the TH-502 employs a分流-type (split-stream) configuration, where a reference beam bypasses the exhaust stream while a measurement beam passes through a standardized sampling tube, enabling real-time differential analysis and minimizing drift from ambient light interference or thermal lensing. This architecture ensures high reproducibility under dynamic engine load conditions, making it suitable for both steady-state and transient emission testing per ISO 8549-1, SAE J1667, and GB/T 3846–2021 protocols.
Key Features
- High-contrast monochrome graphical LCD display with intuitive Chinese-language menu navigation and context-sensitive prompts—designed for rapid operator training and minimal error rate in workshop environments.
- Integrated data logging system capable of storing up to 100 complete test records onboard, including timestamp, engine RPM, measured opacity (%), obscuration value (m−1), peak/minimum/average smoke values, and user-defined test IDs.
- USB interface supporting bidirectional communication with Windows-based PC software for advanced reporting, statistical analysis (e.g., coefficient of variation, trend line fitting), and export to CSV or PDF formats compliant with internal QA documentation requirements.
- Automatic zero and span calibration routine triggered at power-on and configurable via service mode—reducing manual intervention and ensuring traceability to NIST-traceable reference filters (optional accessory).
- Dual-parameter output: simultaneous real-time display of smoke number (SN) and linear obscuration (%), aligned with the Hartridge and Bosch scale conventions used in OEM validation and I/M (Inspection & Maintenance) programs.
- Optical protection system utilizing an active air curtain (“air幕” technology) that creates a laminar boundary layer over critical lens surfaces—significantly extending maintenance intervals and preserving optical alignment stability during prolonged operation in dusty or humid garage settings.
Sample Compatibility & Compliance
The TH-502 is calibrated and validated for use with raw, uncooled, undiluted diesel exhaust sampled directly from tailpipes or probe-equipped dynamometer cells. It accommodates standard 4.5 mm ID sampling tubes (ASTM D1317-compliant) and supports flow rates between 10–30 L/min without pressure-induced signal distortion. The device meets the mechanical and electrical safety requirements of GB 4793.1–2019 (equivalent to IEC 61010-1) and conforms to electromagnetic compatibility (EMC) Class B limits per GB/T 18268.1–2010. While not certified to EU Type Approval (R24/R49) or EPA 40 CFR Part 1065 Subpart J out-of-the-box, its measurement methodology and uncertainty profile are fully compatible with laboratory verification against certified reference smokes (e.g., NIST SRM 2975) and field validation per ISO 11614 Annex C.
Software & Data Management
The companion PC software provides full instrument control, including remote start/stop, adjustable sampling duration (1–60 s), and programmable averaging windows. All acquired data include embedded metadata: operator ID, vehicle VIN (manually entered), test date/time (RTC-synchronized), ambient temperature/humidity (via optional external sensor input), and firmware revision. Audit trails are maintained in SQLite database format with write-protected logs; export functions support GLP/GMP-aligned reporting templates—including signature fields, revision history, and digital time stamps—facilitating integration into LIMS platforms or regulatory submissions requiring FDA 21 CFR Part 11–compliant electronic records.
Applications
- OEM engine development labs performing in-house smoke mapping across speed-load matrices.
- Automotive repair facilities conducting mandatory smoke opacity checks under national I/M programs.
- Environmental monitoring agencies verifying compliance with local diesel emission standards (e.g., China’s CN11/GB 18352.6–2016 Tier 6 limits).
- Third-party certification bodies performing type approval tests on light- and medium-duty diesel vehicles.
- Vocational training institutions teaching exhaust diagnostics and emission control fundamentals.
FAQ
What is the measurement principle used by the TH-502?
It uses split-stream opacimetry based on Beer-Lambert law, comparing attenuated and reference light beams across a fixed-path exhaust sample chamber.
Does the TH-502 require periodic recalibration with certified filters?
Yes—annual verification using NIST-traceable neutral density filters is recommended for metrological continuity; factory calibration certificate is provided with each unit.
Can the TH-502 be used for biodiesel or renewable diesel blends?
Yes—its optical method is fuel-agnostic; however, users must account for potential differences in soot morphology and refractive index when interpreting SN values relative to petroleum diesel baselines.
Is the onboard memory data exportable without the PC software?
No—the USB interface requires the proprietary software for structured data extraction; raw binary dumps are not supported.
What environmental conditions affect measurement accuracy?
Ambient temperatures below 0 °C or above 45 °C may impact photodiode response stability; condensation inside the sampling tube must be avoided via heated line accessories (sold separately).
