IRM ND115 Natural Convection Drying Oven
| Brand | IRM |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | Manufacturer |
| Country of Origin | Domestic (China) |
| Model | ND115 |
| Temperature Range | Ambient +5°C to 220°C |
| Temperature Fluctuation | ±1.0°C |
| External Dimensions | 660 × 750 × 810 mm |
| Internal Dimensions | 500 × 450 × 510 mm |
| Temperature Resolution | 0.1°C |
| Control System | PID-based microprocessor controller with self-tuning capability |
| Timer Range | 0–9999 minutes or 0–9999 hours |
| Safety Features | Independent overtemperature protector, door interlock switch, residual-current circuit breaker (RCCB), overcurrent/overvoltage protection, triple overtemperature protection (heating cutoff at set deviation limit, alarm-triggered cutoff, hardware-independent backup cutoff) |
| Optional Accessory | Temperature data logger |
Overview
The IRM ND115 Natural Convection Drying Oven is an engineered thermal processing instrument designed for precise, uniform, and repeatable drying, curing, sterilization, and conditioning of non-volatile or low-volatility samples in academic, industrial, and quality control laboratories. Unlike forced-air ovens, this model relies on natural convection—heat transfer driven solely by buoyancy-induced air movement—to eliminate mechanical airflow interference, thereby minimizing sample disturbance, particle resuspension, or moisture redistribution during extended thermal exposure. Its chamber geometry, insulation integrity, and thermal mass distribution are optimized to ensure minimal vertical and horizontal temperature gradients across the working volume. The oven operates within a calibrated range of ambient +5°C to 220°C, with a documented temperature fluctuation of ≤±1.0°C under steady-state conditions—a specification validated per ISO 17025-compliant internal verification protocols. It complies with IEC 61010-1:2010 safety requirements for laboratory electrical equipment and incorporates fail-safe architecture aligned with GLP and GMP environmental monitoring prerequisites.
Key Features
- Precision PID microprocessor controller with auto-tuning functionality, enabling stable setpoint acquisition and adaptive response to load or ambient variations
- 0.1°C temperature resolution and real-time digital display via backlit LCD interface with intuitive touch-sensitive keypad navigation
- Configurable timer function supporting dual-range operation: 0–9999 minutes (for short-duration processes) or 0–9999 hours (for extended stability testing or aging studies)
- Triple-layer overtemperature protection system: (1) software-configurable upper limit cutoff, (2) positive-deviation alarm with immediate heating termination, and (3) physically isolated mechanical overtemperature protector independent of main control logic
- Door interlock switch that de-energizes heating elements upon door opening—preventing operator exposure to elevated surface temperatures and ensuring thermal process integrity
- Integrated residual-current circuit breaker (RCCB), overcurrent protection, overvoltage suppression, and sensor fault detection with audible/visual alert
- Temperature offset correction function allowing user-defined calibration adjustment to compensate for systematic drift or chamber-specific thermal asymmetry
Sample Compatibility & Compliance
The ND115 accommodates a broad spectrum of solid and semi-solid materials including pharmaceutical excipients, polymer pellets, ceramic green bodies, metal powders, filter papers, glassware, and standard reference materials used in gravimetric moisture analysis (e.g., ASTM E121, ISO 712). Its natural convection design avoids turbulent airflow, making it suitable for delicate particulates, hygroscopic substances, or samples requiring undisturbed settling during desiccation. The stainless-steel interior (SUS304 grade), rounded corners, and seamless welds support routine cleaning and meet basic hygiene requirements for non-sterile applications. While not certified for Class II biological safety or explosion-proof use, the unit satisfies CE marking criteria under the Low Voltage Directive (2014/35/EU) and Electromagnetic Compatibility Directive (2014/30/EU). Documentation packages include factory calibration reports traceable to NIM (National Institute of Metrology, China) standards.
Software & Data Management
The ND115 operates as a standalone instrument without embedded network connectivity; however, its analog output (0–5 V or 4–20 mA, optional) supports integration into centralized SCADA or LIMS environments for remote monitoring. When equipped with the optional temperature data logger, continuous time-stamped readings are recorded at user-selectable intervals (1 s to 60 min), stored in CSV format on removable SD card, and exportable for audit-ready reporting. All logged data includes timestamp, chamber temperature, setpoint, and status flags (e.g., “HEATING”, “ALERT”, “IDLE”). The logging module conforms to FDA 21 CFR Part 11 principles through password-protected configuration, electronic signature capability, and immutable audit trail generation—facilitating compliance in regulated pharmaceutical and food testing workflows.
Applications
- Moisture content determination per AOAC 950.46 and USP <731> Loss on Drying (LOD) procedures
- Pre- and post-weighing conditioning of filters, crucibles, and weighing boats prior to gravimetric analysis
- Curing of adhesives, coatings, and composite pre-pregs under controlled thermal ramp profiles
- Stability testing of raw materials and intermediates under accelerated aging protocols (ICH Q1A)
- Drying of geological core samples, soil specimens, and agricultural biomass for dry-weight normalization
- Thermal equilibration of reference standards and calibration artifacts before metrological evaluation
FAQ
Is the ND115 suitable for drying volatile organic solvents?
No. This natural convection oven lacks explosion-proof construction, solvent recovery systems, or inert gas purging capability. It is intended only for aqueous or low-volatility matrix drying.
Can the temperature uniformity be verified independently?
Yes. The internal dimensions (500 × 450 × 510 mm) allow placement of up to nine calibrated PT100 probes per ICH Q5C Annex 2 guidance. Uniformity mapping is supported by the oven’s stable thermal profile and absence of fan-induced turbulence.
What maintenance is required to sustain ±1.0°C performance?
Annual verification using NIST-traceable reference thermometers is recommended. Routine inspection of door gasket integrity, heater element continuity, and sensor mounting position ensures long-term repeatability.
Does the ND115 support programmable ramp-soak cycles?
No. As a natural convection unit, it features only single-setpoint temperature control with timer-based termination—not multi-segment thermal profiling.
Is third-party IQ/OQ documentation available?
Yes. IRM provides customizable qualification templates (including test protocols, acceptance criteria, and execution records) compatible with ISO/IEC 17025 and GxP laboratory validation frameworks.
