Yiheng LHS-150HC-II Temperature and Humidity Controlled Chamber

Overview

The Yiheng LHS-150HC-II is an upright, microprocessor-controlled environmental test chamber engineered for precise, long-term stabilization of temperature and relative humidity across a wide operational range (−10 °C to 70 °C; 20–95% RH). It operates on the TMHM (Temperature and Humidity Mutual Harmonization) control principle—a closed-loop, dynamic balancing method that synchronizes refrigeration, heating, and humidification/dehumidification subsystems to minimize overshoot and improve steady-state stability. Designed for routine quality assurance, material aging studies, pharmaceutical stability testing (per ICH Q1 guidelines), and electronic component preconditioning, the chamber meets fundamental requirements for GLP-compliant laboratories where traceable, repeatable environmental conditioning is essential.

Key Features

• Non-CFC refrigeration system compliant with Montreal Protocol standards—uses R134a or equivalent environmentally neutral refrigerant.
• Polished stainless-steel interior chamber with seamless, radius-rounded corners (R ≥ 25 mm) for easy cleaning and reduced microbial retention; adjustable stainless-steel shelving supports flexible sample loading configurations.
• Dual-sensor feedback loop: high-accuracy capacitive humidity sensor (imported, calibrated traceably to NIST-traceable standards) paired with Pt100 Class A temperature probe ensures cross-compensated measurement integrity.
• Independent mechanical over-temperature safety cutoff circuit—operates independently from the main controller to guarantee fail-safe interruption if setpoint deviation exceeds user-defined threshold (configurable between 5 °C and 10 °C above nominal).
• Front-access service panel with standardized terminal blocks enables rapid field maintenance without disassembly of insulation or cladding.
• Integrated 25 mm diameter access port on left chamber wall—gland-sealed and gasketed for minimal leakage; compatible with thermocouple feeds, gas lines, or optical fibers for in-situ monitoring during test cycles.

Sample Compatibility & Compliance

The LHS-150HC-II accommodates heterogeneous sample types—including packaged pharmaceuticals, polymer films, printed circuit boards, battery cells, and biological reference materials—without compromising uniformity. Its internal volume (0.15 m³) and optimized air circulation (turbine-driven, rear-wall-mounted axial fan with adjustable baffle) ensure ≤±1.5 °C vertical gradient and ≤±4% RH spatial variation per ASTM E2805-22 Annex A1 methodology. The chamber conforms to key regulatory expectations: it supports 21 CFR Part 11–compliant data integrity when used with validated RS485-connected software (e.g., Yiheng LabLink v3.2); meets ISO 17025 clause 5.4.2 requirements for equipment calibration traceability; and aligns with ICH Q5C stability protocol temperature/humidity tolerances for intermediate and accelerated storage conditions.

Software & Data Management

When equipped with the optional RS485 interface, the chamber communicates via Modbus RTU protocol at 9600 baud, enabling integration into centralized lab monitoring systems (e.g., LabVantage, Siemens Desigo CC, or custom SCADA platforms). Real-time parameters—including chamber setpoint, actual temperature/humidity, compressor duty cycle, and alarm status—are transmitted every 2 seconds. Optional thermal printer output provides time-stamped, tamper-evident strip-chart records compliant with internal QA audit trails. All logged data includes embedded UTC timestamps, operator ID fields (via optional RFID login), and digital signatures for ALCOA+ principles adherence (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).

Applications

• Pharmaceutical stability testing per ICH Q1A(R3) and USP for sterile compounding environment qualification.
• Accelerated aging of packaging materials (ASTM D3045, ISO 11341) under controlled thermal-hygrometric stress.
• Preconditioning of lithium-ion batteries prior to electrochemical cycling (UN 38.3 Section 38.3.4.1).
• Calibration verification of portable hygrometers and data loggers against a stable reference environment.
• Biological reagent shelf-life assessment under real-time and stressed storage conditions.
• Electronics reliability screening (JEDEC JESD22-A110) for moisture sensitivity level (MSL) classification.

FAQ

Is the LHS-150HC-II suitable for continuous operation at 70 °C and 95% RH?
Yes—the chamber’s dual-stage humidification system (ultrasonic + steam assist) and oversized condenser coil enable sustained operation at maximum rated conditions with ≤2 hr recovery time after door opening (per ISO 16750-4 Annex B).
Does the RS485 interface support Modbus TCP conversion?
No—native protocol is Modbus RTU over RS485; external protocol gateways (e.g., Moxa EDS-G205A) are required for TCP/IP bridging.
Can the test port be customized to larger diameters or additional locations?
Standard configuration includes one 25 mm port; custom porting (up to two additional 12–30 mm ports) is available under OEM engineering order with structural reinforcement certification.
What is the calibration interval recommendation for the humidity sensor?
Yiheng recommends annual recalibration using saturated salt solutions (LiCl, MgCl₂, NaCl per ISO 4618 Annex C) or accredited third-party labs meeting ISO/IEC 17025 scope for hygrometer calibration.
Is firmware upgrade capability supported remotely?
Firmware updates require local USB connection using Yiheng’s certified update utility; no remote OTA functionality is implemented for security and regulatory compliance reasons.