OK-ZTH-390 Walk-in Environmental Test Chamber

Overview

The OK-ZTH-390 Walk-in Environmental Test Chamber is a fully engineered, structural-grade environmental simulation system designed for laboratory- and production-level validation of large-scale components, subsystems, and integrated equipment under controlled thermal stress conditions. Unlike benchtop or upright climatic chambers, the OK-ZTH-390 functions as a walk-in enclosure—engineered with load-bearing steel framing, high-density insulated panel construction, and a personnel-accessible sealed entry door—enabling direct operator intervention during test execution. Its core operational principle relies on precision air-handling via forced convection, supported by a dual-stage cascade refrigeration system (high-temperature and low-temperature compressors), high-capacity electric heating banks, and a distributed airflow network optimized for spatial temperature uniformity across the full working volume. This architecture supports stable steady-state operation and programmable thermal cycling per IEC 60068-2-1 (cold), IEC 60068-2-2 (dry heat), and ISO 16750-4 (road vehicles). The chamber is not intended for humidity control; it is a dedicated thermal-only system, distinguishing it from walk-in temperature-humidity chambers.

Key Features

• Structural chamber design with 100 mm thick polyurethane (PU)-filled sandwich panels (double-skin galvanized steel), offering thermal conductivity ≤ 0.022 W/m·K and fire-retardant certification (B1 grade per GB 8624)
• Reinforced steel framework capable of supporting ceiling-mounted instrumentation, cable trays, and internal test fixtures
• Large access door (800 × 1,900 mm) with multi-point pneumatic latching, double-glazed observation window, anti-frost heater, and safety interlock circuitry
• Cascade refrigeration system using R404A/R23 refrigerant pair, enabling reliable operation down to −70 °C without liquid nitrogen dependency
• High-efficiency axial and centrifugal circulation fans with adjustable vane diffusers to maintain ≤ ±2 °C temperature uniformity (measured at 9-point sensor grid per ASTM E744)
• Programmable PLC-based controller with 10.4″ color touchscreen, Ethernet interface, real-time data logging (≥10,000 data points), and user-defined ramp-soak profiles (up to 99 segments)
• Dedicated test ports (6 × Φ50 mm, sealable with silicone grommets) for power, signal, and sensor feedthroughs, maintaining thermal integrity during operation
• Comprehensive safety architecture: over-temperature cut-off, compressor high-pressure shutdown, phase failure protection, and door-open alarm with automatic cooling suspension

Sample Compatibility & Compliance

The OK-ZTH-390 accommodates physically large or thermally active test articles—including automotive battery modules (up to 1.2 m × 0.8 m footprint), industrial inverters, telecom cabinets, aerospace avionics racks, and photovoltaic string combiners. Its 0.39 m³ usable volume (700 × 800 × 700 mm) allows for unrestricted placement of DUTs with ≥150 mm clearance from walls and ceiling to ensure laminar airflow distribution. The chamber meets mechanical and electrical safety requirements per GB/T 5171.1–2014 (low-voltage equipment) and complies with electromagnetic compatibility standards GB/T 17626.2/3/4. While not certified to UL or CE for export use out-of-the-box, its architecture aligns with the foundational design principles of IEC 60068-3-5 (environmental test methods—specifications for temperature chambers) and supports audit readiness for internal quality systems operating under ISO 9001 and IATF 16949 frameworks. Optional validation packages (IQ/OQ) are available upon request to support GLP-compliant qualification.

Software & Data Management

The embedded controller runs proprietary firmware supporting CSV export of time-stamped temperature logs (min/max/avg per cycle), alarm history with timestamps, and profile versioning. Remote monitoring is enabled via Modbus TCP or OPC UA (optional add-on), permitting integration into centralized MES or SCADA platforms. All logged data includes metadata: operator ID, chamber ID, test ID, and UTC timestamp—ensuring traceability per FDA 21 CFR Part 11 when paired with external electronic signature workflows. Audit trails record parameter changes, manual overrides, and system events with immutable timestamps. Data retention is configurable up to 12 months onboard; external USB backup is supported. No cloud connectivity is enabled by default—data sovereignty remains local unless explicitly commissioned.

Applications

• Automotive: Cold-start validation of EV powertrains at −40 °C; thermal soak testing of ADAS ECUs; battery pack thermal runaway propagation studies under controlled ambient offsets
• Energy Storage: BESS cabinet thermal cycling (−20 °C ↔ +60 °C) per UL 9540A pre-conditioning protocols; inverter derating analysis at elevated ambient temperatures
• Telecommunications: Base station radio unit (RRU) performance verification across extended temperature ranges; server rack thermal management validation under simulated datacenter edge conditions
• Aerospace & Defense: Ground-based thermal vacuum pre-test conditioning of satellite payloads; environmental screening of UAV flight controllers prior to altitude chamber exposure
• Industrial Electronics: Burn-in qualification of industrial PLCs and HMIs; accelerated life testing of motor drives under sustained thermal stress

FAQ

What is the maximum allowable heat load from the DUT during operation?
The standard OK-ZTH-390 is rated for up to 1.5 kW continuous internal heat dissipation. For higher loads (e.g., powered battery systems), derating curves and custom refrigeration upgrades must be specified during quotation.
Can this chamber be integrated with external data acquisition systems?
Yes—via analog 4–20 mA or 0–10 V outputs for chamber temperature, or digital Modbus RTU/TCP registers mapping all critical process variables.
Is field installation and commissioning included?
Standard delivery includes factory pre-commissioning and full technical documentation. On-site assembly, leveling, refrigerant charging, and IQ/OQ validation are optional services billed separately.
Does the chamber support thermal shock testing?
No—the OK-ZTH-390 is configured for controlled ramp-and-soak profiles only. For thermal shock applications, OK Instruments offers the separate OK-TS series with dual-zone independent chambers and transfer mechanisms.
What maintenance intervals are recommended?
Compressor oil and filter replacement every 3,000 operating hours; annual calibration of internal PT100 sensors against NIST-traceable references; quarterly inspection of door gaskets and electrical terminations.