OK Instruments OK-TH-5 Programmable Temperature and Humidity Chamber

Overview

The OK Instruments OK-TH-5 Programmable Temperature and Humidity Chamber is an engineered environmental test system designed for precise, repeatable simulation of climatic conditions across a wide operational envelope. It operates on the principle of dual-loop independent control—separate PID-regulated refrigeration, heating, humidification, and dehumidification subsystems—enabling stable maintenance of temperature and relative humidity (RH) under dynamic programmed profiles. The chamber is constructed with a stainless-steel inner chamber, high-efficiency insulation (polyurethane foam, ≥100 mm thick), and a double-glazed observation window with anti-fog coating. Its benchtop form factor integrates compact footprint with industrial-grade performance, making it suitable for QC labs, R&D facilities, and regulatory-compliant stability testing environments where space efficiency and traceable environmental control are critical.

Key Features

• Programmable multi-segment controller with intuitive 7-inch color touchscreen interface supporting up to 100 program segments, unlimited cycles, jump-to-step, hold, and real-time monitoring.
• Independent temperature and humidity control architecture ensures high reproducibility across complex ramp-soak profiles—including simultaneous rapid transitions (e.g., −40 °C → +85 °C in <30 min) and low-humidity holds at sub-zero temperatures.
• Air-cooled refrigeration system with hermetic scroll compressor, copper-aluminum finned evaporator, and electronic expansion valve enables reliable operation from −40 °C to +150 °C without liquid nitrogen or external chiller dependency.
• Steam-based humidification using stainless-steel immersion heater and demineralized water reservoir; ultrasonic humidifier optional for faster response in low-mass applications.
• Comprehensive safety suite: over-temperature cut-off, compressor overheat/overcurrent protection, dry-run alarm for humidifier, water-level sensor, ground-fault circuit interrupter (GFCI), and door interlock switch.
• Standard communication interfaces include RS-232, RS-485, and Ethernet (TCP/IP), enabling integration with LabVIEW, SCADA systems, or custom MES platforms.

Sample Compatibility & Compliance

The OK-TH-5 accommodates diverse sample geometries and material classes within its 210 L internal volume (700 × 600 × 500 mm). Perforated stainless-steel shelves ensure uniform airflow distribution per IEC 60068-3-5 and ISO 16750-4 requirements. The chamber supports test protocols aligned with ASTM D4332 (conditioning of plastics), ISO 4892-2 (plastics—UV exposure), IEC 60068-2-30 (damp heat, cyclic), MIL-STD-810H Method 507.6, and JIS Z 8702. For pharmaceutical applications, optional validation packages support IQ/OQ/PQ documentation and comply with FDA 21 CFR Part 11 data integrity requirements—including audit trail, electronic signature, and user access control when used with OK’s certified LogViewPro software.

Software & Data Management

OK LogViewPro is a Windows-based data acquisition and analysis platform compatible with the OK-TH-5. It provides real-time graphing of temperature/humidity trends, automatic generation of test reports in PDF/Excel format, and configurable alarm notifications via email or SMS. All logged data are stored with timestamped metadata (operator ID, program name, chamber ID), supporting GLP/GMP traceability. Raw data files are saved in CSV and binary formats with SHA-256 checksums to prevent tampering. Optional cloud synchronization enables remote supervision across distributed lab networks while maintaining local data sovereignty.

Applications

• Electronics Reliability: Thermal cycling and damp heat testing of PCBAs, connectors, and semiconductor packaging per JEDEC JESD22-A104 and A110.
• Automotive Components: Validation of infotainment modules, battery management systems (BMS), and ADAS sensors under combined thermal-humidity stress per ISO 16750-4 and LV-124.
• Materials Aging: Accelerated weathering studies of elastomers, coatings, adhesives, and fiber-reinforced composites per ASTM D5894 and ISO 11341.
• Pharmaceutical Stability: Long-term and accelerated stability testing of drug substances and products per ICH Q1A(R3), including 25 °C/60 % RH and 30 °C/65 % RH storage condition simulations.
• Renewable Energy: Environmental stress screening of photovoltaic module backsheets and lithium-ion pouch cells under high-humidity high-temperature (HHHT) conditions per IEC 61215-2 MQT 10.1.

FAQ

What is the minimum recommended sample volume relative to chamber capacity?
For optimal airflow uniformity and thermal/hygrometric stability, samples should occupy no more than 66% of internal chamber volume. Minimum free air space around samples is 100 mm from walls, 50 mm from ceiling/floor, and unobstructed clearance above/below shelves.
Can the chamber maintain 10% RH at −40 °C?
No. The practical lower humidity limit is constrained by dew point physics: at −40 °C, saturation RH is ~0.1%. The specified 20–98% RH range is achievable only within the temperature band of +10 °C to +85 °C per ISO 16750-4 Annex B.
Is distilled water mandatory for humidification?
Yes. Use of deionized or distilled water (conductivity <5 µS/cm) is required to prevent mineral deposition on the steam generator and wet-bulb sensor, which would degrade long-term humidity accuracy and necessitate premature maintenance.
Does the OK-TH-5 support automated calibration verification?
Yes. The chamber includes built-in calibration ports for NIST-traceable reference probes. OK Instruments provides optional automated calibration verification kits compliant with ISO/IEC 17025 procedures, including uncertainty budgets and certificate generation.
What is the expected service interval for preventive maintenance?
Under standard operating conditions (8 hrs/day, ambient 23 ±3 °C), compressor oil and refrigerant charge require inspection every 24 months; humidifier tank cleaning and wet-bulb wick replacement every 3 months; full sensor recalibration annually by an accredited third-party laboratory.