Yoyi DHG-9140A Forced-Air Constant-Temperature Drying Oven

Overview

The Yoyi DHG-9140A is a precision-engineered forced-air constant-temperature drying oven designed for reproducible thermal processing in regulated laboratory and industrial quality control environments. Based on convective heat transfer principles, it employs a rear-mounted centrifugal blower and optimized air duct architecture to ensure uniform airflow distribution across the working chamber. This design enables consistent thermal exposure—critical for applications requiring adherence to standardized drying, baking, sterilization, or moisture removal protocols. The unit operates within a calibrated temperature range of RT+10 °C to 250 °C, with a typical fluctuation of ±1.0 °C and uniformity of ±2.5% (measured at 100 °C under no-load conditions per GB/T 30435–2013). Its robust construction—including cold-rolled steel exterior with electrostatic epoxy coating and mirror-finish stainless-steel interior—ensures long-term dimensional stability and resistance to chemical exposure during routine cleaning and maintenance.

Key Features

• Microprocessor-based PID temperature controller with 0.1 °C resolution, real-time display of setpoint, actual chamber temperature, and remaining timer duration
• Dual-layer tempered glass observation window with integrated seal, enabling non-intrusive visual monitoring without compromising thermal integrity
• High-efficiency air circulation system featuring adjustable rear inlet/exhaust ports and directional ducting to minimize thermal stratification
• Intelligent power-loss recovery function: automatically resumes prior operating parameters (set temperature, timer, mode) after unexpected interruption
• Independent over-temperature cut-off circuit (optional), compliant with IEC 61000-4-2 for fail-safe operation
• Modular accessory interface supporting RS485 serial communication (Modbus RTU), embedded thermal printer, inert gas purging port with calibrated float flowmeter (0–10 L/min), and multi-segment programmable controller
• Adjustable stainless-steel shelving (2 standard trays included), rated for static loads up to 15 kg per shelf

Sample Compatibility & Compliance

The DHG-9140A accommodates a broad spectrum of sample types—including biological specimens, polymer films, pharmaceutical excipients, ceramic precursors, electronic components, and metal coatings—without risk of cross-contamination or catalytic degradation. Its stainless-steel chamber complies with ISO 14644-1 Class 8 cleanroom material requirements for particulate generation. The oven meets GB/T 30435–2013 (Chinese national standard for electric hot-air drying ovens), and its thermal performance validation methodology aligns with ASTM E2209 (Standard Practice for Calibration of Laboratory Ovens). Optional configurations support GLP/GMP documentation workflows via audit-trail-enabled data logging (when paired with RS485 + compliant software), and optional inert gas purging enables oxygen-sensitive processes per USP sterilization guidelines.

Software & Data Management

When equipped with the RS485 interface module, the DHG-9140A integrates seamlessly into centralized laboratory information management systems (LIMS) or SCADA platforms. The supplied Windows-compatible software provides time-stamped temperature logging at user-defined intervals (1 s to 60 min), exportable in CSV or PDF format for regulatory submission. All logged data includes operator ID, session timestamp, environmental metadata (ambient T/RH), and device firmware version—meeting FDA 21 CFR Part 11 requirements for electronic records when deployed with appropriate access controls and digital signature modules. Optional embedded thermal printers generate hard-copy run reports compliant with ISO/IEC 17025 clause 7.8.2.

Applications

• Moisture content determination in food, feed, and agricultural products per AOAC 950.46 and ISO 665
• Pre-conditioning of polymeric test specimens prior to tensile or impact testing (ASTM D618, ISO 291)
• Drying of filter papers, crucibles, and volumetric glassware in analytical chemistry workflows
• Thermal aging studies of insulating materials in electrical engineering (IEC 60216)
• Baking of PCB substrates and solder paste reflow simulation in electronics manufacturing
• Depyrogenation of glassware and stainless-steel components in pharmaceutical cleanrooms (USP )
• Heat treatment of calibration standards and reference materials in metrology labs

FAQ

What is the maximum operating temperature, and is it validated across the full chamber volume?
The DHG-9140A is rated for continuous operation up to 250 °C. Temperature uniformity is verified at three critical points (center, top-back corner, bottom-front corner) per GB/T 30435–2013 using NIST-traceable Class A PT100 probes.
Can the oven be used for sterilization applications?
While not classified as a medical-grade sterilizer, the unit achieves dry-heat sterilization conditions (e.g., 160 °C for 120 min) suitable for depyrogenation of glassware and metal instruments per USP . Validation must be performed per site-specific SOPs.
Is the RS485 interface compatible with LabVIEW and Python-based automation frameworks?
Yes—the Modbus RTU protocol implementation supports native integration with LabVIEW’s Modbus I/O libraries and Python’s pymodbus or minimalmodbus packages for script-driven temperature ramping and data acquisition.
How often does the unit require recalibration, and what documentation is provided?
Annual calibration is recommended. Each unit ships with a factory calibration certificate listing as-found/as-left values at 100 °C, 150 °C, and 200 °C, traceable to CNAS-accredited standards.
Are custom internal dimensions or voltage configurations available?
Yes—Yoyi offers OEM engineering services for non-standard chamber geometries, dual-voltage (110/220 VAC) variants, and explosion-proof modifications (ATEX Zone 2 / IECEx certified upon request).