HUANKONG GHK-8702 Constant Temperature & Humidity Weighing System
| Brand | HUANKONG |
|---|---|
| Origin | Shandong, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | GHK-8702 |
| Pricing | Available Upon Request |
Overview
The HUANKONG GHK-8702 Constant Temperature & Humidity Weighing System is an engineered environmental control platform designed specifically for gravimetric analysis of airborne particulate matter in regulatory-compliant air quality monitoring and source apportionment studies. It integrates a high-precision analytical balance within a sealed, actively controlled chamber that maintains stable temperature (typically 20.0 ± 0.5 °C) and relative humidity (typically 40.0 ± 2.0 % RH) — parameters mandated by key U.S. EPA and Chinese environmental standards for filter-based mass determination. The system operates on the principle of conditioned stabilization: samples (e.g., quartz fiber or PTFE membrane filters loaded with PM2.5, PM10, or stack emission particulates) are equilibrated under rigorously defined thermohygrometric conditions prior to and during weighing, eliminating hygroscopic drift and thermal buoyancy artifacts that compromise measurement reproducibility. This architecture ensures traceable, ISO/IEC 17025-aligned gravimetric data suitable for regulatory submission.
Key Features
- Optimized air circulation design with laminar, low-turbulence airflow distribution to achieve spatial uniformity of temperature and humidity across the entire weighing chamber (±0.3 °C, ±1.5 % RH deviation at working volume)
- Digital PID-controlled environmental regulator with dual-sensor feedback loop for independent, high-stability temperature and humidity setpoint maintenance
- Modular sample staging system accommodating standardized 47 mm, 90 mm, and 110 mm filter holders, as well as custom trays for sorbent tubes or cascade impactor substrates
- Multi-stage vibration isolation base integrated beneath the balance mounting platform, including pneumatic damping and constrained-layer damping materials to suppress floor-borne and acoustic disturbances
- Twin access ports fitted with extended nitrile-latex composite gloves, enabling operator intervention without chamber breach or environmental perturbation
- Double-glazed observation window with anti-fog coating and integrated LED illumination (5000 K CCT, <1 lux flicker) for real-time visual verification of sample placement and balance stability
Sample Compatibility & Compliance
The GHK-8702 supports all standard filter media used in regulatory particulate mass measurement, including quartz fiber, Teflon-coated glass fiber, polyvinyl chloride (PVC), and polycarbonate membranes. Its environmental performance conforms to the conditioning requirements specified in HJ 836–2017 (for low-concentration stack particulate measurement), HJ 618–2011 (ambient PM10/PM2.5 gravimetry), and HJ 656–2013 (PM2.5 manual monitoring technical specifications). While not certified to ISO 17025 itself, the system enables laboratories to meet the environmental control clauses of ISO/IEC 17025:2017 Clause 6.3.2 and ASTM D7520–19 Annex A1 for gravimetric method validation. Chamber internal dimensions (W × D × H: 650 × 520 × 580 mm) accommodate up to 24 standard 47-mm filters simultaneously.
Software & Data Management
The GHK-8702 operates via embedded controller firmware with local touchscreen interface (7-inch capacitive display) supporting programmable conditioning cycles, event logging (timestamped temperature/humidity/balance readings), and USB export of CSV-formatted environmental logs. When interfaced with external analytical balances compliant with RS-232 or USB-HID protocols (e.g., METTLER TOLEDO XSR, SARTORIUS Entris), raw mass data can be synchronized with chamber environmental metadata. Audit trail functionality records all parameter changes, door openings, and calibration events — supporting GLP documentation requirements. Optional integration with LIMS platforms is achievable via Modbus TCP or OPC UA gateways for automated data ingestion into enterprise QA/QC workflows.
Applications
- Pre- and post-sampling gravimetric analysis of ambient and stack particulate filters per national and provincial environmental monitoring programs
- Method validation and routine QC for PM2.5 and PM10 reference methods in accredited environmental testing laboratories
- Source apportionment studies requiring ultra-low detection limits (<1 µg/filter) and inter-laboratory comparability
- Stability testing of filter substrates under controlled hygrothermal stress
- Calibration verification of low-flow samplers using microgram-level mass gain protocols
FAQ
What temperature and humidity setpoints does the GHK-8702 support?
The system is factory-configured for 20.0 °C / 40.0 % RH per HJ 618–2011, but user-adjustable setpoints range from 15–30 °C and 30–60 % RH with corresponding stability tolerances.
Is the chamber compatible with Class I or Class II biological safety cabinets?
No — the GHK-8702 is a closed, non-ventilated conditioning chamber; it is not rated for biosafety containment or negative-pressure operation.
Can the system be validated per ISO 17025 requirements?
Yes — while the unit itself is not accredited, its environmental performance can be verified using NIST-traceable thermohygrometers and documented per ISO/IEC 17025 Clause 6.3.2 and ILAC-G8:2022 guidelines.
Does the GHK-8702 include balance calibration tools?
No — balance calibration remains the responsibility of the end-user laboratory; the system provides stable mounting and environmental isolation to maximize balance performance.
What power supply and ambient room conditions are required?
220 V AC ±10 %, 50 Hz; ambient operating environment: 15–30 °C, <70 % RH non-condensing, minimal air draft exposure.
