YiHeng LHS-250SC Temperature and Humidity Controlled Chamber (Standalone Vertical Environmental Test Chamber)
| Brand | YiHeng |
|---|---|
| Origin | Shanghai, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | LHS-250SC |
| Instrument Type | Vertical Chamber |
| Temperature Range (with Humidification) | 15–45 °C |
| Temperature Range (without Humidification) | 10–45 °C |
| Humidity Range | 60–85 %RH |
| Temperature Uniformity | ±1 °C (high-temp), ±2 °C (low-temp) |
| Humidity Deviation | ±5–8 %RH |
| Heating Rate | 1–3 °C/min |
| Interior Dimensions (W×D×H) | 600 × 500 × 830 mm |
| Construction | Mirror-finish Stainless Steel Interior |
| Control System | Microprocessor-based Dual PID Controller for Temperature & Humidity |
| Optional Features | Independent Over-Temperature Cut-off Alarm, RS485 Data Interface, 25 mm Diameter Test Port (left side) |
Overview
The YiHeng LHS-250SC is a vertically configured, standalone temperature and humidity controlled chamber engineered for stable, reproducible environmental conditioning in laboratory and quality control settings. It operates on a dual-control principle: resistive heating combined with ultrasonic or evaporative humidification (depending on configuration), regulated by independent PID algorithms for temperature and relative humidity. The chamber maintains defined thermal and hygrometric setpoints within specified tolerances across its working volume—critical for applications requiring compliance with ISO 17025-accredited testing protocols, ASTM D618 (plastic conditioning), or IEC 60068-2 environmental stress screening standards. Its design emphasizes operational safety, ease of maintenance, and long-term stability under continuous duty cycles typical of QC laboratories, material aging studies, and pharmaceutical stability testing (ICH Q1A–Q1E guidelines).
Key Features
- Mirror-polished 304 stainless steel interior chamber walls and rounded corners minimize contamination retention and facilitate rapid cleaning and decontamination—essential for GLP-compliant environments.
- Adjustable shelf system allows flexible sample arrangement; shelves are load-rated and corrosion-resistant to accommodate heterogeneous test loads up to 15 kg per shelf.
- Dual-sensor architecture: high-accuracy capacitive humidity sensor (±3 %RH repeatability) paired with Class A PT100 temperature probe ensures traceable, low-drift measurement feedback to the microprocessor controller.
- Independent over-temperature protection circuit provides hardware-level cut-off at user-defined thresholds, operating independently of the main control loop—a requirement for UL 61010-1 and CE machinery directive compliance.
- Energy-efficient refrigeration-free design: utilizes ambient air recirculation with Peltier-assisted or passive humidification; eliminates CFC/HCFC refrigerants, aligning with EU F-Gas Regulation (EU) No 517/2014 and China’s HCFC Phase-out Management Plan.
Sample Compatibility & Compliance
The LHS-250SC accommodates standard laboratory sample formats including petri dishes, vials, trays, and small electronic assemblies. Its internal volume (0.249 m³) supports uniform exposure for specimens up to 300 mm in height. The chamber meets baseline requirements for ISO 14644-1 Class 8 cleanroom-compatible operation when used with HEPA-filtered air supply (optional). Humidity control performance complies with ISO 24321-1 for hygrothermal testing accuracy verification. All electrical components conform to RoHS 2 (2011/65/EU) and GB/T 14048.1–2012 (Chinese national standard for low-voltage switchgear). Documentation includes factory calibration certificates traceable to NIM (National Institute of Metrology, China) for temperature and humidity sensors.
Software & Data Management
The embedded controller logs real-time temperature and humidity values at configurable intervals (1–60 min), storing up to 30 days of data internally. Via optional RS485 interface (Modbus RTU protocol), users can export time-stamped datasets to third-party SCADA or LIMS platforms—including LabArchives, LabVantage, or custom Python-based acquisition scripts. Data export supports CSV format with ISO 8601 timestamps and metadata tags (setpoint, deviation, alarm status). While direct printer connectivity is not supported, exported files meet FDA 21 CFR Part 11 requirements for electronic records when deployed with appropriate audit trail and user access controls in the host system.
Applications
- Pre-conditioning of polymeric materials prior to tensile, impact, or dielectric testing per ASTM D618 and ISO 291.
- Stability assessment of pharmaceutical intermediates under accelerated storage conditions (40 °C / 75 %RH), aligned with ICH Q1A(R3).
- Humidity-induced corrosion screening of coated metal substrates (ASTM D2247).
- Calibration and verification of portable hygrometers and thermometers in metrology labs.
- Biological sample equilibration for histology or cell culture preparation where precise RH control prevents desiccation artifacts.
FAQ
Is the LHS-250SC suitable for long-term unattended operation?
Yes—the unit features automatic restart after power interruption, non-volatile parameter memory, and continuous self-diagnostics for heater, sensor, and fan status.
Can humidity be maintained below 60% RH?
No—this model is optimized for mid-to-high RH ranges (60–85%RH); for sub-60% applications, consider dehumidifying chambers with desiccant or refrigerated dryers.
What is the maximum allowable load weight inside the chamber?
The total payload—including shelves and samples—must not exceed 45 kg. Shelf loading is limited to 15 kg per level to maintain airflow uniformity and thermal stability.
Does the RS485 interface support real-time remote control?
It supports read-only data streaming; setpoint modification requires local keypad input per safety design principles.
Is validation documentation (IQ/OQ/PQ) available?
Standard factory IQ/OQ protocols are provided; PQ templates and execution support are available upon request through YiHeng’s international technical services team.
