OK-STH Series Large-Scale Environmental Test Chamber

Overview

The OK-STH Series Large-Scale Environmental Test Chamber is an industrial-grade, modular walk-in climatic chamber engineered for long-term, high-reliability environmental simulation across aerospace, automotive, electronics, and materials science applications. Unlike standard reach-in chambers, the OK-STH platform employs Balanced Temperature and Humidity Control (BTHC)—a closed-loop thermodynamic regulation method that dynamically coordinates refrigeration output, electric heating power, and steam humidification rate to maintain setpoint stability without overshoot or oscillation. Its structural architecture integrates stainless steel inner walls with high-density rigid polyurethane insulation (≥150 mm), achieving thermal resistance values exceeding R-30 (SI: ≥5.3 m²·K/W). Designed for continuous 24/7 operation under GLP and ISO 17025-aligned laboratory conditions, the system supports temperature extremes from −65°C to +80°C and humidity ranges spanning 20–98% RH—validated per IEC 60068-3-5 and ASTM E145 Annex A4.

Key Features

• Modular panel-based construction using interlocking heat-resistant sandwich panels—enabling on-site assembly in constrained facilities with minimal civil works.
• Redundant hardware architecture: dual-stage compressor protection (high-pressure cut-off, oil temperature monitoring, phase failure detection), independent heater circuit isolation, and fail-safe humidifier dry-run prevention.
• Intelligent specimen safeguard logic: user-configurable thermal lockout thresholds; automatic heater de-energization when internal sensor readings exceed preset limits—preventing thermal damage to sensitive DUTs (Devices Under Test).
• Passive pressure equalization: mechanical relief door activated at +50 Pa over ambient—ensuring structural integrity during rapid humidity ramping or sealed-condition testing.
• Energy-adaptive control algorithm: real-time load estimation adjusts refrigeration capacity and reheating duty to minimize power consumption without compromising setpoint fidelity.
• Human-machine interface: 10.1″ capacitive touchscreen controller with multi-language support (EN/DE/FR/ES), embedded data logging (10,000-point buffer), and configurable alarm escalation protocols.

Sample Compatibility & Compliance

The OK-STH accommodates large-format test specimens—including EV battery modules (up to 2 m × 1.5 m × 0.3 m), avionics enclosures, solar panel arrays, and medical device sterilization validation loads. Internal dimensions are fully customizable (standard options: 2×2×1 m to 5×2×4 m), with reinforced floor loading capacity up to 1,200 kg/m². All models comply with electromagnetic compatibility per EN 61326-1, safety requirements under EN 61010-1, and environmental stress screening guidelines per MIL-STD-810H Method 502.5 (Temperature) and Method 507.6 (Humidity). Optional configurations meet FDA 21 CFR Part 11 requirements for electronic records and signatures when paired with validated Ethernet-enabled data loggers and audit-trail-enabled firmware.

Software & Data Management

The integrated controller supports local data capture at 1-second intervals, exportable via USB to CSV or Excel-compatible formats. Optional networked operation enables remote monitoring through HTTP/HTTPS web interface or Modbus TCP integration into facility SCADA systems. For regulated environments, the optional GLP-compliant data logger provides time-stamped, tamper-evident records with full audit trail (user login/logout, parameter changes, alarm events), meeting ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available). Firmware updates are delivered via signed binary packages with SHA-256 verification.

Applications

• Aging validation of lithium-ion battery packs under combined thermal-humidity cycling (e.g., UN 38.3 T1–T5 protocols).
• Environmental stress screening (ESS) of automotive ECUs per ISO 16750-4 and SAE J2309.
• Accelerated corrosion testing of coated metal substrates using cyclic salt-spray/humidity profiles (ASTM B117 + G85 Annex A5).
• Stability testing of pharmaceutical packaging per ICH Q1A(R2) and USP .
• Pre-conditioning of composite materials prior to mechanical testing (ASTM D5229/D5229M).
• Calibration lab support for reference sensor characterization across extended climate envelopes.

FAQ

What is the maximum allowable internal pressure differential before the equalization door activates?
The mechanical pressure relief door opens automatically at +50 Pa above ambient atmospheric pressure—verified via calibrated diaphragm transducer calibration traceable to NIST standards.
Can the chamber operate continuously at −65°C and 10% RH simultaneously?
Standard configuration supports −65°C at ≥20% RH. Achieving sub-10% RH at cryogenic temperatures requires the optional deep-dry dehumidification system with desiccant wheel and secondary refrigeration stage.
Is the controller firmware validated for 21 CFR Part 11 compliance?
The base controller does not include electronic signature or audit trail functionality. These capabilities are enabled only with the optional GLP Data Logger module and require site-specific IQ/OQ validation documentation.
What maintenance intervals are recommended for the refrigeration system?
Compressor oil analysis and filter dryer replacement every 3,000 operating hours; full refrigerant circuit leak check and charge verification annually—or per ISO 5149-2:2014 maintenance schedules.
Does the chamber support automated test sequencing across multiple setpoints?
Yes—the touchscreen HMI supports up to 99 programmable steps per profile, including ramp/soak segments, humidity transitions, and conditional branching based on real-time sensor feedback.