DRETOP FRH-55AC Benchtop Temperature and Humidity Controlled Chamber

Overview

The DRETOP FRH-55AC is a precision-engineered benchtop temperature and humidity controlled chamber designed for accelerated environmental stress testing under tightly regulated climatic conditions. It operates on the principle of dual-loop independent control—separate PID-regulated systems govern refrigeration, heating, and humidification subsystems—to ensure stable, repeatable, and traceable environmental profiles across extended test durations. Unlike generic incubators or storage chambers, the FRH-55AC meets the functional requirements of IEC 60068-2, ISO 16750-4, and ASTM D4332 for environmental conditioning of electronic components, medical devices, polymers, and pharmaceutical packaging. Its compact footprint (55 L internal volume) makes it suitable for integration into QA/QC laboratories, R&D workbenches, and pilot-scale validation environments where spatial constraints preclude floor-standing units—without compromising thermal-hygrometric fidelity or long-term operational stability.

Key Features

• High-fidelity dual-sensor monitoring: Integrated high-accuracy capacitive humidity sensor (±2.5% RH typical uncertainty above 10% RH) and PT100-class temperature sensor (±0.15 °C at 25 °C), both calibrated per ISO/IEC 17025-accredited procedures.
• Intelligent PID + fuzzy logic control algorithm: Enables dynamic compensation for load-induced thermal lag and humidity hysteresis, minimizing overshoot during ramp-and-soak cycles and maintaining ≤±0.5 °C / ±3% RH steady-state deviation over 24-hour continuous operation.
• Dual-layer insulated chamber architecture: 80 mm thick high-density polyurethane foam (λ = 0.022 W/m·K) sandwiched between outer cold-rolled steel and inner 304 stainless steel mirror panels—achieving surface condensation resistance <0.5 g/m²·h at 85% RH/60 °C ambient.
• Optimized airflow design: Axial fan-driven horizontal laminar circulation with baffle-guided flow ensures uniform distribution (≤±1 °C spatial gradient across working volume per IEC 60068-3-5).
• Modular mechanical assembly: Hermetic scroll compressor (Embraco or equivalent), copper-aluminum microchannel condenser, and stainless steel ultrasonic humidifier enable field-replaceable service with <15-minute downtime for component swap—no specialized tools required.

Sample Compatibility & Compliance

The FRH-55AC accommodates standard test specimens up to 300 mm in height and 250 mm in width on its two adjustable 304 stainless steel shelves. Its Ø25 mm side port (standard) supports feedthrough of thermocouples (Type K/T), humidity probes, power cables, or gas lines—enabling real-time in-chamber parameter logging, powered aging tests, or inert atmosphere purging (N₂/air). The chamber complies with electrical safety standards IEC 61010-1 (Class I, Pollution Degree 2) and electromagnetic compatibility per EN 61326-1. While not certified for Class III medical device validation out-of-the-box, its data integrity architecture—including timestamped audit trails, user-level access control, and non-volatile memory retention—supports alignment with FDA 21 CFR Part 11 and EU Annex 11 requirements when deployed with validated software protocols.

Software & Data Management

The 7-inch color TFT touchscreen interface runs embedded Linux-based firmware with native support for up to 100 multi-segment programs (each with up to 99 steps), including ramp-soak-hold, cycling, and stepwise humidity modulation. All runtime data—including chamber setpoints, actual readings, alarm events, and door-open duration—are logged at user-selectable intervals (1 s to 60 min) into internal 2 GB flash memory. Data export is performed via USB 2.0 mass storage mode (CSV format, UTF-8 encoded); no proprietary drivers or cloud dependencies are required. Optional RS485 Modbus RTU interface enables integration with SCADA systems or centralized lab management platforms (e.g., LabWare LIMS, Siemens Desigo CC) for automated reporting and remote supervision.

Applications

• Electronics reliability: Thermal cycling (−20 °C ↔ 125 °C) and damp heat (85 °C/85% RH) testing per JEDEC JESD22-A104 and A110 for PCB assemblies, IC packages, and automotive ECUs.
• Pharmaceutical stability: ICH Q1A(R2)-aligned long-term (25 °C/60% RH) and accelerated (40 °C/75% RH) storage condition simulation for primary packaging qualification.
• Polymer aging: Oxidative degradation studies of elastomers and thermoplastics under controlled humidity loads to assess hydrolysis kinetics and tensile property decay.
• Medical device verification: ISO 11607-1 compliance testing for sterile barrier system integrity under variable humidity exposure prior to peel strength and burst testing.
• Material science research: Hygroscopic expansion coefficient measurement of composites and ceramics using in-situ dimensional metrology through the double-glazed observation window.

FAQ

What is the minimum operating temperature when humidity is active?
Humidity control is disabled below +4 °C to prevent condensation-induced sensor drift and internal frost accumulation. For sub-zero thermal-only testing, the chamber maintains −20 °C with humidity set to 0% RH.
Can the chamber be operated continuously for 30 days without maintenance?
Yes—under nominal load (<60% volume occupancy) and ambient conditions ≤30 °C/60% RH, the FRH-55AC is rated for unattended 720-hour operation. Daily visual inspection of water reservoir level and air intake filter is recommended.
Is the stainless steel interior electropolished or mechanically polished?
The 304 stainless steel inner chamber uses mechanically polished mirror finish (Ra ≤ 0.4 µm), providing corrosion resistance equivalent to ASTM A480 Grade 2B while enabling effective wipe-down cleaning with IPA or diluted NaOH solution.
Does the USB data export include metadata such as operator ID and calibration certificate expiry?
By default, exported CSV files contain timestamps, setpoint/actual values, and event flags only. Operator ID and calibration metadata require manual entry into the “Notes” field prior to test initiation; these are appended as header comments in the CSV.
What is the maximum allowable load weight on each shelf?
Each 304 stainless steel shelf is load-rated to 15 kg uniformly distributed. Total chamber payload must remain ≤25 kg to maintain specified temperature/humidity uniformity per IEC 60068-3-5 Annex B.