OK-TH-225 Temperature and Humidity Controlled Environmental Test Chamber

Overview

The OK-TH-225 Temperature and Humidity Controlled Environmental Test Chamber is an industrial-grade climatic test system engineered for precise, repeatable simulation of temperature and humidity stress conditions across extended operational cycles. It operates on a balanced heating, cooling, and humidification control principle—commonly referred to as Balanced Temperature and Humidity Control (BTHC)—where PID-regulated solid-state relays (SSRs) dynamically modulate power to resistive heaters, refrigeration compressors, and steam/humidification systems to maintain equilibrium between thermal/hygrometric input and chamber load dissipation. This architecture ensures long-term stability under static and dynamic test profiles, supporting reliability validation, environmental stress screening (ESS), and accelerated life testing of electronic components, automotive modules, aerospace avionics, medical devices, and packaging materials.

Key Features

• Integrated safety architecture: dry-run protection for steam humidifier, independent overtemperature cutoff (dual-stage), low-water-level interlock, compressor overload/overheat/overcurrent monitoring, high-pressure refrigerant switch, molded-case circuit breaker, and residual-current device (RCD) for personnel and equipment protection.
• Advanced BTHC control logic with auto-tuning PID algorithm ensures minimal overshoot and rapid stabilization—critical for compliance with tight tolerance requirements in MIL-STD-2164A and GJB 1032A ESS protocols.
• Full-capillary tube expansion system replaces conventional thermostatic expansion valves (TXVs), delivering superior refrigerant flow consistency, reduced maintenance intervals, and improved low-temperature stability below −20°C.
• Ergonomic chamber design featuring seamless arc-corner interior, non-reflective stainless-steel walls, flat-panel door with ergonomic handle, and front-accessible service panels for filter replacement and condensate drainage.
• Touchscreen controller with multi-language UI (English, Chinese, Spanish), programmable step-and-ramp profiles (up to 99 segments), real-time trend logging, and USB data export—compatible with optional Ethernet/RS485 interfaces for SCADA integration.

Sample Compatibility & Compliance

The OK-TH-225 accommodates test specimens up to 150 kg gross mass and dimensions ≤ 500 × 500 × 500 mm (W×D×H), with customizable internal configurations including shelf supports, cable ports, and mounting rails. Its thermal and hygrometric performance is validated per ISO/IEC 17025-accredited procedures under no-load, ambient conditions of 25°C ± 6°C. The chamber meets the technical requirements of multiple international and defense standards—including GB/T 2423.1–2023 (cold), GB/T 2423.2–2023 (dry heat), IEC 60068-2-1:2022 (cold), IEC 60068-2-2:2022 (dry heat), GJB 1032A–2021 (environmental stress screening), and MIL-STD-2164A–2017 (electronic equipment ESS). All control firmware and data logs support audit-ready traceability aligned with GLP and GMP documentation practices.

Software & Data Management

The embedded controller records time-stamped temperature and humidity values at user-defined intervals (1 s to 60 min), storing up to 10,000 hours of continuous data internally. Exported CSV files include metadata such as setpoint history, alarm events, and system status flags (e.g., heater ON/OFF, compressor cycling, humidifier active). Optional PC-based software enables remote monitoring, multi-chamber synchronization, statistical process control (SPC) charting, and PDF report generation compliant with FDA 21 CFR Part 11 requirements—including electronic signatures, audit trails, and role-based access control.

Applications

• Environmental stress screening (ESS) of printed circuit board assemblies (PCBAs) and embedded controllers per MIL-STD-2164A.
• Temperature-humidity bias testing of lithium-ion battery cells and modules under IEC 62660-2.
• Accelerated aging of polymer-based medical device housings per ISO 11607-1.
• Validation of HVAC component durability under cyclic dew-point exposure.
• Reliability qualification of automotive ECUs per AEC-Q200 and ISO 16750-4.
• Stability testing of pharmaceutical primary packaging per ICH Q1A(R2) guidelines.

FAQ

What is the minimum achievable humidity at −40°C?
At −40°C, the practical lower limit is approximately 30% RH due to condensation constraints and sensor accuracy degradation; operation below this point is not recommended.
Can the chamber operate without external cooling water?
No—the OK-TH-225 requires chilled water supply (10–28°C, 0.1–0.3 MPa) for condenser heat rejection during sustained low-temperature operation; air-cooled variants are available upon request.
Is the controller compliant with FDA 21 CFR Part 11?
The base controller supports audit trails and password-protected parameter changes; full 21 CFR Part 11 compliance requires optional software license and server-based validation package.
How is temperature uniformity verified?
Uniformity is measured using nine calibrated PT100 sensors placed at standardized locations (center + eight corners) per IEC 60068-3-5, with results documented in the factory calibration certificate.
What maintenance intervals are recommended?
Humidifier tank cleaning every 72 operating hours; refrigerant oil and filter replacement every 2,000 hours; annual verification of sensor calibration and safety interlocks by authorized service technician.