OK Instruments OK-STH Series Walk-in Environmental Test Chamber
| Brand | OK Instruments |
|---|---|
| Origin | Guangdong, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | OK-STH (Custom Volume Options: 5, 10, 20, 50, 100 m³) |
| Temperature Range | −40 °C to +150 °C |
| Temperature Uniformity | ≤ ±2 °C |
| Temperature Control Accuracy | ±1 °C |
| Heating Rate | Up to 3 °C/min |
| Cooling Rate | Up to 1 °C/min |
| Humidity Range | 10–98% RH |
| Humidity Uniformity | ±2–3% RH |
| Humidity Control Accuracy | ±0.1% RH (at stable condition) |
| Refrigeration System | Single-stage or cascade (dual-stage) refrigeration |
| Compressor | Hermetic Tecumseh (France) |
| Controller | YX-880 Touchscreen PID Controller (Hong Kong) |
| Construction | Exterior – Premium Color-Coated Steel |
| Power Supply | AC 1φ 220 V / 3φ 220/380 V, 50/60 Hz |
| Safety Protections | Leakage Circuit Breaker, Over-Temperature Protector, Phase-Loss Protector, Low-Water-Level Cut-off |
Overview
The OK Instruments OK-STH Series Walk-in Environmental Test Chamber is an industrial-grade, large-volume climate simulation system engineered for precise, reproducible, and long-duration thermal and hygrothermal conditioning of components, subsystems, and finished products. Based on the principle of forced-air convection with dual independent control loops—electrical resistive heating and steam-based humidification coupled with cascade refrigeration—the chamber delivers tightly regulated temperature and relative humidity profiles across volumetric test spaces ranging from 5 to 100 m³. Its structural architecture supports static and dynamic environmental stress screening (ESS), accelerated life testing (ALT), and qualification-level validation per MIL-STD-810, IEC 60068, and GB/T 2423 series standards. Designed for continuous operation in production QA labs, R&D centers, and third-party certification facilities, the OK-STH integrates robust mechanical construction with fail-safe thermal management and audit-ready operational logging.
Key Features
- Modular walk-in design with customizable internal dimensions—standard configurations available in 5, 10, 20, 50, and 100 m³ volumes; non-standard footprints accommodated via engineering consultation.
- Dual-stage (cascade) refrigeration system utilizing hermetically sealed Tecumseh compressors for reliable sub-zero performance down to −40 °C and rapid thermal transitions.
- PID-controlled touchscreen interface (YX-880) with real-time graphing, multi-segment programmable profiles, and password-protected parameter locking for GLP/GMP compliance.
- SUS304 stainless steel interior lining and high-density polyurethane insulation (≥120 mm thickness) ensure corrosion resistance, low thermal leakage, and long-term dimensional stability.
- Integrated safety interlocks including over-temperature cutoff, phase-loss detection, water-level monitoring for steam humidifier, and ground-fault circuit interruption (GFCI).
- Large observation window with double-glazed, anti-fog tempered glass enables visual monitoring without compromising chamber integrity or thermal load.
- Optional data logging module compliant with FDA 21 CFR Part 11 requirements—including electronic signatures, audit trail, and exportable CSV/Excel reports.
Sample Compatibility & Compliance
The OK-STH chamber accommodates full-size assemblies such as automotive ECUs, avionics enclosures, server racks, medical imaging systems, and battery packs up to 3 m in height and 2.5 m in width. Its uniformity specifications (≤ ±2 °C temperature, ±2–3% RH) meet the spatial homogeneity requirements defined in IEC 60068-3-5 and GB/T 2423.1–2423.4. The system conforms to national and international standards including GB 11158, GB/T 10586, GJB 150.3/4/9, and ISO 16750-4 for automotive environmental testing. All electrical components are rated for continuous duty under Class II pollution conditions and comply with CE marking directives (EMC Directive 2014/30/EU and Low Voltage Directive 2014/35/EU).
Software & Data Management
The embedded YX-880 controller provides intuitive touch navigation, up to 100 programmable test steps, and real-time deviation alerts. Optional PC-based software (OK-EnviroLink v3.2) enables remote monitoring, automated report generation, and integration with LIMS or MES platforms via Modbus TCP or RS-485. Data archives include timestamped temperature/humidity readings, alarm logs, setpoint history, and compressor runtime—all stored locally on SD card with automatic backup to network drives. For regulated environments, the optional 21 CFR Part 11 package adds role-based access control, electronic signature workflows, and immutable audit trails traceable to NIST-traceable calibration records.
Applications
- Aerospace component qualification per DO-160 Section 4 (temperature) and Section 5 (humidity)
- Automotive electronics validation under ISO 16750-4 and SAE J1211 thermal cycling protocols
- Pharmaceutical stability chamber mapping and ICH Q1A–Q1E compliance studies
- Battery thermal runaway propagation testing at elevated ambient conditions
- Defense system ESS (Environmental Stress Screening) per MIL-STD-810H Method 501.7 and 502.7
- Industrial IoT gateway and edge computing hardware burn-in under combined thermal-hygric loads
FAQ
What is the standard lead time for a custom-configured OK-STH chamber?
Standard delivery for configured units is 8–12 weeks from order confirmation, subject to volume specification and optional feature selection.
Can the chamber be validated for IQ/OQ/PQ protocols?
Yes—OK Instruments provides factory-issued IQ/OQ documentation packages, including sensor calibration certificates (NIST-traceable), uniformity mapping reports, and installation verification checklists.
Is remote diagnostics supported?
All OK-STH units include Ethernet connectivity and support SNMP-based health monitoring; optional cloud telemetry enables predictive maintenance alerts via OK’s secure portal.
How is humidity generated and controlled?
Steam humidification using stainless-steel immersion heaters ensures fast response and minimal mineral deposition; RH control employs dew-point referenced feedback with PID tuning optimized for low-drift operation.
What maintenance intervals are recommended?
Compressor oil and refrigerant levels should be verified annually; steam generator descaling every 6 months; air filter replacement quarterly; full system calibration every 12 months by authorized service personnel.
