YiHeng LHS Series Temperature and Humidity Controlled Chamber (Professional Grade)
| Brand | YiHeng |
|---|---|
| Origin | Shanghai, China |
| Model | LHS Series |
| Temperature Range (I) | -5 to 60°C |
| Temperature Range (II) | -10 to 80°C |
| Humidity Range (I) | 40–85% RH |
| Humidity Range (II) | 40–95% RH |
| Temperature Resolution | 0.1°C |
| Temperature Uniformity | ±0.5°C (high temp), ±1°C (low temp) |
| Humidity Accuracy | ±3% RH (I-type), ±5–8% RH (II-type) |
| Power Input | 680–2200 W |
| Internal Dimensions (W×D×H, mm) | 400×400×500 to 600×500×830 |
| Standard Shelving | 2–3 adjustable stainless-steel shelves |
| Interface Options | RS485 port, optional thermal printer |
| Test Port | Ø25 mm (left side, except LHS-150SC/LHS-250SC) |
| Compliance | Designed for ISO 17025-aligned environmental testing workflows, compatible with GLP/GMP documentation requirements via optional data logging |
Overview
The YiHeng LHS Series Temperature and Humidity Controlled Chamber (Professional Grade) is an engineered environmental test system designed for precise, repeatable simulation of controlled temperature and relative humidity conditions. Based on dual-loop PID control architecture—separate proportional-integral-derivative algorithms for refrigeration/dehumidification and heating/humidification subsystems—the chamber maintains stable setpoints across a wide operational envelope. Its thermodynamic design integrates forced-air convection with insulated double-wall construction and mirror-finish 304 stainless-steel interior surfaces to minimize thermal gradients and condensation artifacts. This architecture ensures compliance with critical regulatory expectations for stability-indicating testing in pharmaceutical development (e.g., ICH Q1A–Q1E), accelerated aging per ASTM F1980, and material performance validation under defined climatic stressors.
Key Features
- Environmentally compliant refrigeration system utilizing R134a or R600a zero-ozone-depletion refrigerants—fully fluorine-free design aligned with EU F-Gas Regulation and EPA SNAP guidelines.
- Mirror-polished 304 stainless-steel interior chamber with radius-corner geometry (≥R25 mm) enables full-surface cleanability and eliminates microbial harborage points—validated for ISO 14644-1 Class 7 cleanroom-compatible operation.
- Dual-sensor humidity control using calibrated capacitive polymer sensors (imported origin), eliminating reliance on wet-bulb/dry-bulb psychrometry and associated calibration drift or wick maintenance.
- Independent over-temperature cut-off circuit (optional) meeting IEC 61000-4-2/IEC 61000-4-4 immunity standards—automatically de-energizes heating elements upon exceeding user-defined safety threshold.
- Modular interface architecture: standard RS485 Modbus RTU protocol support enables integration into centralized lab monitoring systems (e.g., LabVantage, Thermo Fisher SampleManager); optional thermal printer provides real-time hardcopy traceability per FDA 21 CFR Part 11 Annex 11 principles.
- Ergonomic access design includes left-side Ø25 mm test port (standard on HC models), removable shelving with 25 mm vertical pitch adjustment, and tool-free door gasket replacement.
Sample Compatibility & Compliance
The LHS Series accommodates heterogeneous sample loads—including sealed vials, blister packs, textile swatches, polymer films, and electronic assemblies—without compromising chamber uniformity. Internal airflow distribution is validated per ISO 16750-4 Annex C methodology, ensuring spatial temperature deviation ≤±1.5°C and humidity variation ≤±5% RH across the full working volume (per ICH Q5C storage condition mapping). The chamber supports long-duration uninterrupted operation (>1,000 h) at extreme setpoints (e.g., 40°C/75% RH), fulfilling stability protocol requirements for pharmaceutical registration dossiers. All electrical components comply with CE marking directives (2014/30/EU EMC, 2014/35/EU LVD), and thermal insulation meets EN 60068-3-5 thermal shock resistance classifications.
Software & Data Management
Equipped with a microprocessor-based controller featuring non-volatile memory for up to 10 user-defined programs (each with 99 segments), the system logs timestamped temperature/humidity values at configurable intervals (1–300 s). Optional PC software (YiHeng EnviroLog v3.x) provides audit-trail-enabled data export in CSV/XLSX formats, with digital signature capability for 21 CFR Part 11-compliant electronic records. When paired with the embedded thermal printer (LHS-150SC/250SC models), printed outputs include chamber ID, operator ID, date/time stamp, and deviation alerts—supporting ALCOA+ data integrity principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).
Applications
- Pharmaceutical stability studies per ICH Q1 guidelines (long-term, accelerated, intermediate conditions)
- Packaging integrity evaluation under cyclic humidity exposure (ASTM D4332, ISO 2233)
- Textile hygroscopic equilibrium testing (ISO 139, AATCC 185)
- Electronics moisture sensitivity level (MSL) preconditioning (JEDEC J-STD-020)
- Food product shelf-life modeling under controlled water activity (aw) profiles
- Biological reagent storage validation and cold-chain interruption simulation
FAQ
What is the maximum allowable load volume without compromising temperature/humidity uniformity?
Uniformity specifications are guaranteed up to 70% of internal chamber volume occupancy. For example, in the LHS-250HC-I (600×500×830 mm), loading must not exceed 175 L of solid mass or obstruct rear wall air inlets.
Can the chamber operate continuously at 80°C with 95% RH?
No. The II-type models support 80°C only in dry mode (no active humidification). Maximum simultaneous temperature/humidity is 45°C/95% RH (LHS-250HC-II) due to condensation management constraints.
Is firmware upgrade capability available?
Yes—controller firmware updates are distributed via USB flash drive through the front-panel service port, with version rollback functionality retained for audit continuity.
Does the system support remote monitoring via Ethernet or Wi-Fi?
Native Ethernet/Wi-Fi is not integrated; however, third-party Modbus TCP gateways (e.g., Moxa EDS-205A) may be deployed between the RS485 port and enterprise networks under validated configuration.
How often does the humidity sensor require recalibration?
Certified recalibration is recommended annually against NIST-traceable saturated salt solutions (e.g., Mg(NO₃)₂ for 54% RH, NaCl for 75% RH) per ISO/IEC 17025 Clause 6.5.3.
