OK Instruments OK-TH-225.0 Programmable Temperature and Humidity Environmental Test Chamber

Overview

The OK Instruments OK-TH-225.0 Programmable Temperature and Humidity Environmental Test Chamber is an engineered benchtop solution for precise, repeatable simulation of climatic stress conditions during product qualification, reliability validation, and materials performance evaluation. Based on dual-loop PID-controlled heating, refrigeration, and humidification subsystems, the chamber maintains stable thermal and hygric environments via forced-air convection, high-efficiency heat exchangers, and a microprocessor-regulated steam generator. Its architecture adheres to fundamental principles of psychrometric control and thermodynamic equilibrium—ensuring traceable, reproducible test profiles across defined operational boundaries. Designed for laboratories requiring compliance with international environmental testing standards—including MIL-STD-810G, IEC 60068-2 series, and GB/T 2423—this chamber supports both steady-state and programmable cyclic test sequences, enabling rigorous assessment of electronic components, automotive modules, medical devices, packaging materials, and polymer-based assemblies under controlled thermal-hygrometric loads.

Key Features

• Full-color 7-inch capacitive touchscreen controller with intuitive graphical interface and real-time data visualization; supports seamless English/Chinese language switching without firmware reset
• Double-sealed door assembly incorporating dual-layer high-tension silicone gaskets rated for continuous operation from –40 °C to +150 °C
• Observation window constructed from triple-pane tempered glass with integrated conductive film—enabling unobstructed visual monitoring while preventing condensation and electrostatic interference
• Internal chamber fabricated entirely from electropolished SUS#304 stainless steel, ensuring corrosion resistance, non-outgassing performance, and compatibility with cleanroom-grade maintenance protocols
• One standard Ø50 mm cable/port access opening on the left side wall, fitted with removable rubber grommet and compatible with optional feedthrough adapters for signal/power lines
• Integrated safety architecture featuring independent over-temperature, over-humidity, compressor high-pressure, and phase-failure detection—triggering immediate audible/visual alarm and automatic power isolation
• Modular refrigeration system utilizing environmentally compliant R404A (low-temp stage) and R23 (ultra-low-temp option) refrigerants, coupled with low-noise scroll compressors and optimized finned evaporator design

Sample Compatibility & Compliance

The OK-TH-225.0 accommodates samples up to 600 mm (W) × 750 mm (H) × 500 mm (D), with two adjustable SUS#304 stainless steel shelves included as standard. Its internal geometry permits uniform airflow distribution per ISO 16750-4 Annex C requirements, minimizing thermal stratification and humidity gradients. The chamber meets critical compliance benchmarks for environmental stress screening: IEC 60068-2-1 (cold), IEC 60068-2-2 (dry heat), IEC 60068-2-78 (constant damp heat), and IEC 60068-2-30 (cyclic damp heat). It also satisfies military-grade specifications per MIL-STD-810G Methods 501.6 (high temperature), 502.6 (low temperature), and 507.5 (humidity), supporting GLP-aligned test documentation when paired with optional audit-trail-enabled software modules. Calibration traceability follows ISO/IEC 17025 guidelines through NIST-traceable reference sensors installed at chamber center and corner locations.

Software & Data Management

The embedded controller logs time-stamped temperature and humidity values at user-defined intervals (1–600 seconds), storing up to 100 test programs with 100 segments each (ramp/soak/humidity step profiles). Export is supported via USB 2.0 port in CSV format for post-processing in Excel or statistical analysis platforms (e.g., JMP, Minitab). Optional PC-based OK-EnviroLink software provides remote monitoring, real-time graphing, automated report generation (PDF/Excel), and 21 CFR Part 11-compliant user authentication, electronic signatures, and change audit trails—essential for regulated industries including medical device manufacturing and aerospace component validation.

Applications

• Accelerated life testing of PCBAs, connectors, and semiconductor packages under combined thermal-hygrometric stress
• Validation of seal integrity and moisture barrier performance in pharmaceutical primary packaging (blister packs, vials, pouches)
• Evaluation of dimensional stability and mechanical property retention in engineering plastics (e.g., PEEK, PPS, LCP) across operational humidity bands
• Qualification of battery management systems (BMS) and lithium-ion cells per UN 38.3 thermal cycling protocols
• Environmental screening of automotive ECUs and ADAS sensors under ISO 16750-4-specified temperature-humidity load profiles
• Material aging studies for coatings, adhesives, and elastomers where hydrolytic degradation mechanisms dominate

FAQ

What is the maximum allowable sample mass for thermal stability within the OK-TH-225.0?

The chamber is rated for static thermal load capacity up to 15 kg without compromising specified uniformity or recovery time. For dynamic thermal mass exceeding this threshold, consult factory application engineering for derating guidance.
Can the OK-TH-225.0 perform rapid temperature transitions per IEC 60068-2-14?

Yes—the standard configuration achieves ≥2.0 °C/min average ramp rate between –20 °C and +85 °C. Optional high-speed upgrade kits support up to 5.0 °C/min with enhanced compressor staging and pre-conditioned air bypass.
Is third-party calibration certification available?

NIST-traceable calibration certificates (per ISO/IEC 17025) are available upon request, including as-found/as-left data, uncertainty budgets, and sensor location mapping.
Does the chamber support Ethernet or RS485 communication for integration into lab-wide SCADA systems?

Standard models include RS232 and USB interfaces. RS485 Modbus RTU and Ethernet TCP/IP modules are available as factory-installed options with protocol documentation and driver libraries.
What maintenance intervals are recommended for long-term reliability?

Compressor oil and refrigerant levels should be verified annually; humidity sensor recalibration every 6 months; air filter replacement every 3 months under continuous operation; full system performance verification per ISO 16750-4 Annex D every 24 months.