YiHeng LHS-80HC-I Temperature and Humidity Controlled Chamber (R134a-Free Refrigeration)

Overview

The YiHeng LHS-80HC-I is a precision-engineered upright temperature and humidity controlled chamber designed for stable, long-term environmental simulation in laboratory, quality control, and R&D settings. It operates on a non-ozone-depleting refrigerant (R134a), fully compliant with international environmental directives including the Montreal Protocol and EU F-Gas Regulation (EU No. 517/2014). The chamber employs a balanced thermal-hygrometric control methodology—TMHM (Thermal-Moisture Hybrid Management)—to achieve dynamic equilibrium between heating, cooling, humidification, and dehumidification subsystems. This architecture minimizes overshoot and hysteresis, enabling reproducible environmental conditioning across defined setpoints. Its primary application domain includes stability testing per ICH Q1 guidelines, accelerated aging per ASTM D3574 and ISO 188, material moisture absorption studies, and pre-conditioning of samples prior to mechanical or electrical testing.

Key Features

• Environmentally responsible refrigeration system using R134a refrigerant—zero ozone depletion potential (ODP = 0) and low global warming potential (GWP = 1430).
• Mirror-finished stainless steel interior chamber with radius-rounded corners (R ≥ 25 mm) and adjustable stainless steel shelving—designed for easy cleaning, corrosion resistance, and compliance with GLP laboratory hygiene standards.
• Microprocessor-based dual-channel PID controller with real-time digital display of both temperature and relative humidity; supports ramp-soak programming with up to 8 segments (standard firmware).
• Critical components—including hermetic scroll compressor, centrifugal humidifier fan, and electronic expansion valve—sourced from Tier-1 international suppliers to ensure operational longevity and low maintenance intervals.
• Capacitive polymer humidity sensor (imported, calibrated traceable to NIST standards) mounted within the air circulation path for high-accuracy RH feedback (±1.5% RH typical repeatability at 25°C/50% RH).
• Dual independent safety systems: (1) Mechanical overtemperature cut-off (adjustable 5–80°C), and (2) Electronic limit alarm with relay output and visual/audible alert—fully compliant with EN 61010-1:2019 safety requirements for laboratory equipment.
• Standard 25 mm diameter access port on left side wall, fitted with silicone gasket and brass compression collar—enabling continuous external monitoring (e.g., thermocouple feedthrough, data logger probe insertion) without compromising chamber integrity.

Sample Compatibility & Compliance

The LHS-80HC-I accommodates standard sample configurations including petri dishes, desiccator trays, sealed vials, and small electronic assemblies (max. footprint 350 × 350 mm per shelf). Its uniformity profile meets ISO 16750-4 (automotive electronics environmental testing) and JIS Z 8806 (humidity uniformity classification) Class B specifications (< ±2.5% RH deviation across working volume at 60% RH, 40°C). The chamber is suitable for use under GLP and GMP frameworks when paired with validated calibration procedures (per ISO/IEC 17025) and audit-ready documentation packages. All electrical interfaces conform to CE marking requirements and RoHS 2011/65/EU material restrictions.

Software & Data Management

The LHS-80HC-I supports optional RS485 serial communication (Modbus RTU protocol) for integration into centralized lab monitoring networks. When connected to a host PC running compliant SCADA or LIMS software (e.g., LabVIEW, WinCC, or custom Python-based acquisition tools), users can log time-stamped temperature/humidity data at user-defined intervals (1 s to 60 min resolution). Optional thermal printer interface (IEEE 1284 parallel or USB-emulated) provides hard-copy record generation for audit trails. Data files are exported in CSV format with ISO 8601 timestamping, supporting 21 CFR Part 11-compliant electronic records when deployed with appropriate access controls and electronic signature modules.

Applications

• Pharmaceutical stability studies (ICH Q1A–Q1E) for active pharmaceutical ingredients (APIs) and finished dosage forms.
• Electronics component preconditioning per JEDEC J-STD-033 and IPC/JEDEC J-STD-020.
• Polymer hygroscopicity and dimensional stability evaluation (ASTM D5229/D5229M).
• Seed germination and plant tissue culture incubation under controlled abiotic stress conditions.
• Calibration and verification of portable hygrometers and thermometers against reference-grade chamber conditions.
• Accelerated corrosion testing of coated metals (ISO 9223, ASTM G85 Annex A5) when operated with salt mist supplementation (external generator required).

FAQ

What refrigerant is used in the LHS-80HC-I chamber?

R134a—a chlorine-free hydrofluorocarbon (HFC) with zero ozone depletion potential (ODP = 0), widely accepted under current international environmental regulations.
Is the humidity sensor factory-calibrated and traceable?

Yes—the capacitive polymer sensor is pre-calibrated against NIST-traceable standards at three points (30%, 60%, and 90% RH) at 25°C, with certificate of calibration included.
Can the chamber operate continuously at 85% RH and 40°C?

Yes—this is a rated operating condition; continuous operation is supported by redundant condensate management and anti-drip design in the humidification system.
Does the RS485 interface support Modbus TCP/IP conversion?

No—the native interface is RS485 (2-wire, half-duplex); Modbus TCP/IP requires an external protocol gateway device.
What is the maximum load capacity per shelf?

Each adjustable stainless steel shelf supports up to 15 kg uniformly distributed load; total chamber load must not exceed 40 kg to maintain specified uniformity and recovery performance.