DRETOP ZHS-D250HC Temperature and Humidity Controlled Incubator

Overview

The DRETOP ZHS-D250HC Temperature and Humidity Controlled Incubator is an engineered environmental simulation platform designed for precise, long-term maintenance of temperature and relative humidity (RH) conditions across life science, pharmaceutical, and materials testing applications. It operates on the principle of balanced heating/humidification and refrigeration/dehumidification—where independent control loops for thermal energy input (via Ni-Cr alloy heaters) and moisture delivery (via shallow water pan evaporation), coupled with compressor-driven cooling, dynamically adjust to maintain setpoint stability within defined tolerances. This dual-loop architecture enables reproducible chamber environments essential for stability studies (e.g., ICH Q1A–Q1E), accelerated aging tests, microbial growth assays, and material hygrothermal conditioning. With a nominal internal volume of 250 L and a stainless-steel SUS304 interior, the unit supports GLP-compliant workflows in regulated laboratories where traceability, parameter integrity, and operational continuity are critical.

Key Features

• Programmable 30-stage controller with ramp/soak capability, enabling fully autonomous multi-phase environmental profiles without manual intervention
• High-resolution 0.1 °C temperature resolution and real-time dual-parameter (T/RH) display via intuitive touchscreen interface
• Dual-door observation window: inner tempered glass pane with outer magnetic gasket seal ensures thermal insulation and minimizes condensation
• Optimized air distribution system using axial-flow fans and internal baffle geometry to achieve ≤±2 °C temperature uniformity and ≤±5 %RH humidity uniformity across the working chamber
• Modular refrigeration assembly with built-in compressor delay start, cycle interval protection, and overheat safeguards—designed for continuous operation under load
• SUS304 mirror-finish stainless steel interior with removable, height-adjustable shelves (standard: 3 shelves) facilitating cleaning validation and autoclave-compatible decontamination
• Integrated safety architecture including independent overtemperature cut-off, fan failure detection, and power-loss recovery with non-volatile parameter memory retention
• Left-side test port (Φ50 mm) for external sensor feedthrough or process monitoring integration

Sample Compatibility & Compliance

The ZHS-D250HC accommodates a broad range of sample types—including Petri dishes, multiwell plates, flasks, vials, and packaged product specimens—within its 250 L working volume. Its design aligns with fundamental requirements of ISO 14644-1 (cleanroom air classification support), ASTM E145 (standard specification for gravity-convection and forced-ventilation ovens), and USP (general information on stability testing). While not inherently 21 CFR Part 11 compliant out-of-the-box, the unit’s programmable controller supports audit trail-ready configurations when integrated with validated third-party data logging systems meeting FDA-recommended ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available). The use of R134a or R600a zero-ozone-depletion refrigerants satisfies EU F-Gas Regulation (EU No 517/2014) and aligns with global sustainability mandates.

Software & Data Management

The incubator features an embedded programmable controller with local data logging (up to 10,000 records) and USB export functionality for time-stamped temperature/humidity trend files in CSV format. Optional RS485 Modbus RTU communication enables integration into centralized laboratory information management systems (LIMS) or SCADA platforms for remote monitoring and alarm forwarding. All profile programs—including segment duration, target T/RH values, ramp rates, and hold conditions—are stored with timestamped creation/modification metadata. Parameter changes trigger automatic event logging, supporting basic electronic record integrity per GxP expectations. For full 21 CFR Part 11 compliance, external validation of user access controls, electronic signatures, and audit trail immutability must be performed during IQ/OQ/PQ qualification.

Applications

• ICH-compliant stability testing of pharmaceuticals (long-term, intermediate, and accelerated conditions per Q1A–Q1E)
• Microbial culture under controlled hygrothermal stress for bioburden assessment and preservative efficacy testing
• Textile and polymer aging studies evaluating dimensional stability, tensile strength loss, or colorfastness under cyclic humidity exposure
• Food packaging permeability analysis and shelf-life modeling under variable RH environments
• Seed germination and plant tissue culture requiring strict RH modulation alongside temperature control
• Calibration verification of hygrometers and thermometers using NIST-traceable reference standards

FAQ

What is the maximum allowable ambient temperature for stable operation?
The unit is rated for ambient temperatures between 10–30 °C. Operation above 30 °C may compromise cooling capacity and humidity control fidelity, particularly at high RH setpoints.
Can the incubator maintain humidity below 50% RH?
No—the ZHS-D250HC is optimized for humidification only; its minimum specified RH is 50% when operating within the 0–65 °C temperature range. Dehumidification below ambient RH requires optional desiccant or refrigerated dry air integration.
Is the stainless-steel interior electropolished or passivated?
The SUS304 interior features a standard mirror-finish cold-rolled surface. Electropolishing is not included as standard but can be specified upon request for enhanced corrosion resistance in aggressive sterilization cycles.
Does the controller support Ethernet or Wi-Fi connectivity?
Standard configuration includes only RS485 Modbus RTU. Ethernet or Wi-Fi modules are available as factory-installed options subject to firmware compatibility verification.
How often should the water pan be refilled during continuous 95% RH operation?
At 95% RH and 37 °C, typical evaporation rate is ~350 mL/day. Refill frequency depends on ambient humidity and door-opening frequency; a low-water level alarm is provided to prevent dry-run damage.