Yiheng LHS-150SC / LHS-250SC Temperature and Humidity Controlled Chamber

Overview

The Yiheng LHS-150SC and LHS-250SC Temperature and Humidity Controlled Chambers are engineered for precision environmental simulation in routine quality control, stability testing, and material conditioning applications. These vertical-chamber systems operate on a dual-control principle: resistive heating combined with refrigeration-based cooling and ultrasonic or evaporative humidification—ensuring stable thermal-hygrometric conditions within defined operational envelopes. Designed to meet the functional requirements of ISO 17025-accredited laboratories and GLP-compliant environments, the chambers support standardized test protocols where controlled temperature and relative humidity exposure is critical—such as accelerated aging per ASTM D4329, packaging permeability assessment, or pharmaceutical excipient storage qualification.

Key Features

• Mirror-polished 304 stainless steel interior chamber with seamless, radius-rounded corners for enhanced cleanability and corrosion resistance—minimizing microbial retention and facilitating validation-compatible decontamination procedures.
• Microprocessor-based dual-channel controller featuring a high-stability capacitive humidity sensor and PT100 temperature probe, delivering real-time feedback and closed-loop regulation with programmable setpoint ramping and dwell functions.
• Environmentally compliant refrigeration system utilizing R134a or R600a refrigerant—fully fluorocarbon-free (no CFCs, HCFCs, or HFCs with high GWP), aligned with EU F-Gas Regulation and China’s Green Manufacturing Initiative.
• Independent mechanical over-temperature safety cut-off circuit (optional), physically isolated from the main controller—providing fail-safe thermal protection meeting IEC 61010-1 Class II requirements.
• Modular design allows field-installable options including RS485 serial interface (Modbus RTU protocol) for integration into centralized lab monitoring systems, and a 25 mm diameter access port on the left chamber wall for sensor feedthrough or sample manipulation under controlled conditions.

Sample Compatibility & Compliance

The LHS series accommodates a broad range of sample types—including polymer films, electronic components, pharmaceutical tablets, textile specimens, and biological reference standards—within its two standard chamber volumes. Internal shelf spacing is fully adjustable via pre-punched support rails, enabling flexible configuration for multi-tiered sample arrays. The chambers comply with key international standards for environmental test equipment: GB/T 10586–2018 (Chinese national standard for humidity chambers), ISO 2859-1 (sampling plans for inspection by attributes), and support traceable calibration per ISO/IEC 17025 when used with certified reference hygrometers and thermometers. While not rated for IP or explosion-proof operation, the units are suitable for use in non-hazardous laboratory zones classified under NEC Class I, Division 2.

Software & Data Management

The optional RS485 interface enables continuous acquisition of temperature and humidity readings at user-defined intervals (1 s to 60 min resolution) via third-party SCADA or LIMS platforms. Data logging is performed without proprietary software dependencies—raw values are transmitted in ASCII format with timestamped CRC-verified packets. The controller retains internal event logs (e.g., door openings, alarm triggers, setpoint changes) with time/date stamps, supporting audit trail requirements under FDA 21 CFR Part 11 when paired with validated external recording systems. No built-in printer interface is provided; however, exported CSV files are compatible with Excel-based trend analysis, statistical process control (SPC) charting, and regulatory submission packages.

Applications

• Stability studies for medical device packaging per ISO 11607–2 and ASTM F1980.
• Conditioning of composite materials prior to tensile or impact testing (ASTM D618).
• Long-term storage validation of calibration standards and reference materials.
• Accelerated corrosion testing of coated metals under cyclic humidity exposure (ISO 6270–2).
• Environmental acclimatization of sensors, MEMS devices, and optoelectronic assemblies before functional testing.
• Humidity-dependent degradation analysis of hygroscopic APIs and excipients in pharmaceutical development.

FAQ

What is the maximum allowable ambient temperature for continuous operation?
The chamber is rated for installation in rooms maintained between 15 °C and 30 °C, with ≤70 % RH non-condensing ambient conditions. Operation outside this range may compromise cooling capacity and humidity control fidelity.
Can the unit maintain 60 %RH at 45 °C?
Yes—both models achieve the full specified humidity range (60–85 %RH) across the entire active temperature span (15–45 °C) when equipped with standard humidification hardware.
Is NIST-traceable calibration documentation available?
Factory calibration certificates (per ISO/IEC 17025) are available upon request; on-site verification and adjustment services can be arranged through authorized Yiheng service partners in APAC and EMEA regions.
Are replacement shelves and custom interior fixtures offered?
Standard perforated stainless steel shelves are included; additional shelves, wire mesh trays, and bracket-mounted sample holders are available as configurable accessories.
Does the controller support password-protected parameter modification?
Yes—the microprocessor interface includes multi-level access control (operator, technician, administrator) with configurable password policies and change logging for critical parameters such as setpoints, alarms, and calibration offsets.