OK Walk-in Constant Temperature & Humidity Chamber OK-STH-12m²

Overview

The OK Walk-in Constant Temperature & Humidity Chamber OK-STH-12m² is an industrial-grade environmental simulation system engineered for system-level reliability validation under controlled thermal and hygrothermal conditions. Designed around the fundamental principles of psychrometric control and forced-convection heat transfer, this chamber maintains precise, stable, and spatially uniform temperature (−70°C to +150°C, configurable) and relative humidity (20–98% RH) across its 12 m³ usable volume. Its walk-in architecture—featuring a reinforced structural frame, modular insulated panels, and a large-seal observation door—enables direct human access for instrumenting, monitoring, and servicing full-scale assemblies during test execution. Unlike benchtop or upright chambers, the OK-STH-12m² accommodates complete systems—including electric vehicles, battery energy storage systems (BESS), avionics racks, and telecom cabinets—within a single, reproducible climate environment. This capability supports standardized testing per ISO 16750-4 (road vehicles), IEC 60068-2-1/2/14/30 (environmental testing), and MIL-STD-810H Method 502.7 (low temperature) and Method 507.6 (humidity), ensuring compliance with global product qualification requirements.

Key Features

• Modular double-skin steel enclosure with 150 mm thick high-density polyurethane (PU) insulation (λ ≈ 0.022 W/m·K), minimizing thermal bridging and enabling long-term stability.
• Cascade refrigeration system with dual independent compressor stages (R404A/R23), delivering consistent cooling performance down to −70°C without liquid nitrogen dependency.
• Electrically heated observation door with anti-frost coating and safety interlock, certified to EN 1672-2 for operator protection during active operation.
• High-capacity air circulation: Three variable-frequency centrifugal fans (total airflow ≥ 45,000 m³/h) integrated with symmetrical duct distribution ensure ≤ ±3°C temperature uniformity per IEC 60068-3-5.
• PLC-based control platform with 10.4″ color touchscreen, supporting up to 99 programmable test segments, real-time trend visualization, and alarm-triggered email/SMS notifications.
• Dedicated humidity generation via steam injection (stainless steel boiler) and condensation-based dehumidification, calibrated traceably to NIST-traceable hygrometers.

Sample Compatibility & Compliance

The OK-STH-12m² accommodates physically integrated test articles up to 2.8 m (L) × 1.8 m (W) × 1.8 m (H), with provision for power feedthroughs (up to 3× 32A, 380V AC), signal conduits (IP65-rated), and exhaust ducting for heat-generating loads. It supports load compensation algorithms that dynamically adjust refrigeration output based on real-time internal heat dissipation—critical when testing energized BESS units or server racks. The chamber meets structural and operational requirements of ISO/IEC 17025 accredited laboratories and supports audit-ready documentation including calibration certificates (temperature/humidity sensors per ISO/IEC 17025), system verification reports (per ASTM E2876), and electronic audit trails compliant with FDA 21 CFR Part 11 when paired with optional secure firmware.

Software & Data Management

The embedded OK-EnviroControl™ software provides ISO 17025-aligned data integrity features: time-stamped, tamper-evident CSV/Excel export; user role-based access control (administrator, operator, reviewer); and automatic backup to network-attached storage (NAS) or cloud archive. All temperature and humidity channels are sampled at 1 Hz with 0.1°C/0.1% RH resolution. Optional integration with LabVIEW, MATLAB, or MES platforms enables closed-loop test orchestration and SPC analysis. Historical run logs—including setpoint deviations, compressor runtime, and alarm history—are retained for ≥ 18 months and support root-cause analysis during failure investigations.

Applications

• Automotive: Whole-vehicle cold-start validation at −40°C; HVAC thermal management testing; battery pack cycling under combined temperature-humidity stress (e.g., 85°C/85% RH for 1000 h).
• Aerospace: Environmental screening of UAV airframes and flight control electronics per DO-160G Section 4 (temperature) and Section 10 (humidity).
• Energy Storage: UL 1973 and IEC 62619-compliant thermal runaway propagation studies in multi-module BESS cabinets.
• Telecom Infrastructure: Thermal aging of 5G base station cabinets under cyclic 60°C/95% RH conditions to assess conformal coating durability.
• Industrial Electronics: HALT/HASS pre-screening of rail signaling controllers using rapid ramp profiles (up to 4°C/min) across −20°C ↔ +85°C transitions.

FAQ

What is the maximum allowable internal heat load for sustained operation at −40°C?
The chamber is rated for continuous internal heat dissipation up to 8 kW at −40°C, assuming standard ambient conditions (25°C, 50% RH). Higher loads require derating or optional auxiliary cooling integration.
Can the chamber be validated to IQ/OQ/PQ protocols?
Yes—OK Instruments provides GMP-compliant Installation Qualification (IQ), Operational Qualification (OQ), and Performance Qualification (PQ) documentation packages, including sensor mapping, alarm verification, and profile repeatability testing.
Is remote monitoring supported over corporate IT networks?
Yes—the controller includes built-in Ethernet (TCP/IP), Modbus TCP, and optional VPN tunneling. Secure remote access requires TLS 1.2 encryption and two-factor authentication.
How is humidity uniformity verified across the working volume?
Per ISO 12755, humidity uniformity is confirmed using ≥ nine NIST-traceable capacitive hygrometers placed on a 3×3 grid at mid-height, with results documented in the chamber’s PQ report.
Are spare parts and service support available outside China?
OK Instruments maintains authorized service partners in Germany, USA, and Singapore, with critical spares (compressors, controllers, humidifiers) stocked regionally for ≤ 72-hour dispatch.