Yoyi LHS-250HC Temperature and Humidity Controlled Chamber

Overview

The Yoyi LHS-250HC Temperature and Humidity Controlled Chamber is an upright environmental test chamber engineered for precise, long-term simulation of controlled thermal and hygroscopic conditions. It operates on a dual-loop microprocessor PID control architecture—separately regulating heating, refrigeration, and humidification subsystems—to maintain stable setpoints across its full operational envelope (0–60 °C, 40–95 %RH). The chamber employs a forced-air convection system with optimized airflow distribution via a rear-mounted centrifugal blower and asymmetric wind duct design, ensuring uniform temperature distribution (±1 °C uniformity) and minimal vertical/horizontal gradients within the 250 L workspace. Its structural integrity includes double-glazed observation doors with silicone rubber gaskets, high-efficiency insulation (polyurethane foam, ≥80 mm thick), and a mirror-finish stainless-steel interior with radius-corner construction to prevent microbial retention and simplify cleaning validation—a critical requirement in GLP-compliant laboratories.

Key Features

• Stainless-steel interior (AISI 304) with seamless, semi-circular corner welds and adjustable stainless-steel shelving (standard: 2 shelves, load capacity ≥15 kg/shelf)
• Eco-friendly refrigerant R134a/R406a dual-stage cooling system with overheat/overpressure protection and automatic defrost cycle
• Integrated steam-generation humidification system featuring a stainless-steel water reservoir, submerged tubular heater, and auto-refill interface; humidity control validated against NIST-traceable hygrometers
• Large-format backlit LCD controller with intuitive menu navigation, real-time graphing of T/RH trends, and password-protected parameter locking
• Four independently lockable casters (two swivel with brakes, two fixed) enabling safe repositioning without compromising chamber stability
• Dual-door structure: outer door (tempered glass + aluminum frame) and inner door (silicone-sealed acrylic) minimizing thermal loss during observation
• Comprehensive safety suite: independent mechanical overtemperature limiter, refrigerant leak detection, door-open alarm, and power-fail data retention

Sample Compatibility & Compliance

The LHS-250HC accommodates a broad spectrum of sample formats—including Petri dishes, multi-well plates, culture flasks (up to 5 L), polymer specimens, electronic assemblies, and packaged pharmaceuticals—without compromising environmental fidelity. Its design conforms to internationally recognized environmental testing standards, including GB/T 10586–2006 (Technical Requirements for Damp Heat Test Chambers), GB/T 2424.6–2006 (Performance Verification of Temperature/Humidity Chambers), and GJB/J 3827–1999 (Calibration Procedures for Standard Constant-Temperature and Humidity Chambers). While not certified to IEC 60068 or ISO 16750 by default, its performance metrics meet the tolerance thresholds required for pre-compliance screening in electronics reliability testing (e.g., JEDEC JESD22-A108, IPC-9701) and accelerated aging per ASTM D3045. Optional RS485 interface supports integration into centralized lab monitoring systems compliant with FDA 21 CFR Part 11 when paired with validated third-party software.

Software & Data Management

The embedded controller logs timestamped temperature and humidity values at user-selectable intervals (1–60 min), storing up to 30 days of continuous data internally. Export is supported via USB flash drive (FAT32 format) as CSV files compatible with Excel, MATLAB, or LIMS platforms. Optional RS485 communication enables Modbus RTU protocol integration for SCADA or MES environments. When configured with the optional embedded printer, hard-copy records include chamber ID, operator ID, test program ID, start/stop timestamps, and min/max/mean deviation alerts—all traceable for audit purposes. All firmware updates are delivered via signed binary packages to ensure integrity; configuration backups support version-controlled restoration.

Applications

This chamber serves as a foundational platform for stability-indicating studies in pharmaceutical development (ICH Q1A–Q1E), bioburden assessment under ISO 11737-1, polymer hydrolysis kinetics (ASTM D570), textile moisture regain testing (ISO 6741), PCB moisture sensitivity level (MSL) preconditioning (J-STD-020), and microbiological incubation per CLSI M22-A3. Its extended low-temperature capability (0 °C) enables cold-chain validation simulations, while the wide RH range supports corrosion testing (ISO 9223), desiccant efficacy evaluation, and seed germination protocols requiring stratification. In QC/QA labs, it functions as a reference environment for calibrating hygrometers and validating environmental monitoring systems.

FAQ

What is the recommended maintenance schedule for the humidification system?
Monthly inspection of the water reservoir for scale accumulation and quarterly descaling using 5 % citric acid solution is advised. Replace the deionized water daily if operating above 85 %RH for >12 h/day.
Can the chamber operate continuously at 60 °C and 95 %RH?
Yes—thermal and humidity control remain stable under sustained maximum load; however, compressor duty cycle increases by ~40 %, necessitating adequate ambient ventilation (≥20 cm clearance on all sides).
Is the controller compliant with 21 CFR Part 11 for electronic records?
The base controller provides audit-trail-capable logging but requires third-party validated software and role-based access controls to achieve full Part 11 compliance.
What is the maximum payload weight the shelves can support?
Each shelf is rated for 15 kg uniformly distributed; total internal load must not exceed 45 kg to preserve airflow and thermal uniformity.
Does the chamber support external sensor inputs for chamber mapping?
No native analog input ports exist; however, the RS485 option allows connection to external calibrated sensors via Modbus-compatible data loggers.