OKO-70 Series Ultra-Low Temperature & Humidity Controlled Environmental Test Chamber

Overview

The OKO-70 Series Ultra-Low Temperature & Humidity Controlled Environmental Test Chamber is engineered for precise, repeatable simulation of extreme ambient conditions—from −70°C to +150°C and 20% to 98% relative humidity—under controlled laboratory or production-line settings. Based on the principle of balanced thermal-humidity control (BTHC), the chamber employs a dual-loop PID algorithm to dynamically synchronize heating, refrigeration, and steam humidification outputs, ensuring zero steady-state deviation during long-duration tests. Its twin-stage cascade refrigeration architecture enables stable operation at −70°C without liquid nitrogen assistance, while the integrated auto-load-adjusting capillary system eliminates reliance on mechanical expansion valves—enhancing both temperature ramp reproducibility and system longevity. Designed for mission-critical reliability, the chamber meets full-cycle environmental stress screening (ESS) requirements across aerospace, automotive electronics, and high-reliability semiconductor packaging applications.

Key Features

• Full-range operational capability from −70°C to +150°C with humidity control between 20% and 98% RH—validated per IEC 60068-2-1/-2 and MIL-STD-2164A protocols.
• Patented BTHC control architecture using solid-state relays (SSRs) and multi-zone PID tuning for simultaneous thermal and hygric stability—achieving ±1.0°C temperature uniformity and ±3.0% RH uniformity (measured at 25°C, no load, per GB/T 2423.1–2023 Annex B).
• Hermetically sealed twin-stage refrigeration system utilizing R404A refrigerant (zero ozone depletion potential) and Taikang/Tecumseh scroll compressors—operating below 60 dB(A) under full load.
• Auto-filtered municipal water supply interface eliminating dependency on distilled or deionized water; integrated distillation recovery loop reduces water consumption by up to 40% versus conventional steam generators.
• Comprehensive safety architecture including dry-heater burnout protection, independent overtemperature cutoff (dual-sensor redundancy), low-water-level detection, high-pressure refrigerant monitoring, motor overload/overcurrent tripping, and Class I earth-leakage circuit interruption.
• Modular stainless-steel interior with removable double-tier sample racks, ergonomic non-slip door handle, and front-access service panels for calibration and maintenance compliance.

Sample Compatibility & Compliance

The OKO-70 accommodates test specimens up to 500 mm × 500 mm × 500 mm (W×D×H), with customizable internal dimensions available upon request. Its airflow design conforms to ISO 16750-4:2018 for automotive component testing and supports standardized mounting configurations per IPC-J-STD-020D for moisture sensitivity level (MSL) profiling. All units undergo factory verification against national metrological standards (CNAS-accredited third-party calibration certificate included) and are traceable to NIST and PTB reference standards. The chamber satisfies regulatory audit requirements for GLP-compliant environmental validation, including full data integrity per FDA 21 CFR Part 11 (electronic signature support via optional software module) and documented change control logs.

Software & Data Management

Equipped with OKO-Link™ v4.2 embedded controller firmware, the system provides intuitive touchscreen HMI with multilingual UI (English, German, Japanese, Korean, Simplified Chinese). Real-time trend logging records temperature, humidity, setpoint deviation, alarm status, and compressor runtime at user-selectable intervals (1 s to 60 min). Raw data exports to CSV or Excel-compatible formats; optional Ethernet/IP or Modbus TCP integration enables centralized SCADA linkage. Audit trails—including operator login history, parameter modification timestamps, and calibration event records—are retained for ≥12 months and exportable for QA review. Firmware updates are delivered via secure HTTPS OTA protocol with SHA-256 signature verification.

Applications

This chamber serves as a primary tool for environmental stress screening (ESS), accelerated life testing (ALT), and qualification per MIL-HDBK-344 and JEDEC JESD22-A108. Typical use cases include: thermal cycling of PCBAs prior to burn-in; cold-soak validation of lithium-ion battery modules; humidity-induced corrosion assessment of conformal-coated sensors; MSL classification (per J-STD-020) of plastic-encapsulated microcircuits; and pre-shipping environmental conditioning of medical device housings (ISO 13485-aligned). Its −70°C capability supports cryogenic material embrittlement studies and low-temperature performance verification of optical adhesives and elastomeric seals.

FAQ

What is the minimum achievable temperature with full humidity control?

The chamber maintains 20–98% RH down to −40°C; below this, humidity control is disabled to prevent condensation-induced frost accumulation. At −70°C, only dry-cold operation is active.

Does the unit comply with FDA 21 CFR Part 11 for electronic records?

Yes—when equipped with OKO-Link™ Secure Mode (optional), it provides role-based access control, electronic signatures, and immutable audit trails meeting Part 11 Subpart B requirements.

Can tap water be used directly without pretreatment?

Yes—the built-in 5-micron sediment filter and activated carbon stage enable direct connection to municipal water lines; no external RO or DI system is required.

Is third-party calibration certification included with shipment?

Yes—a CNAS-accredited calibration report (traceable to NIM, China) covering temperature and humidity sensors across the full operating range is supplied with each unit.

What is the typical cooling water requirement for optimal −70°C performance?

Chilled water supply must be maintained between 10°C and 28°C at 0.1–0.3 MPa pressure; recirculating chillers with 3 kW cooling capacity are recommended for continuous operation.