| Model | SN886-25m3 |
| Sample Restrictions | This test equipment is prohibited from testing or storing the following samples: Flammable, explosive, or volatile substances Corrosive substances Biological samples Strong electromagnetic emission sources |
| Nominal Volume | 25m3 |
| Inner Chamber Dimensions | W2500 × H2500 × D4000 mm |
| Outer Chamber Dimensions | W3550 × H3130 × D4650 mm |
| Test Environmental Conditions | Ambient temperature 5–35°C; relative humidity ≤85%RH; atmospheric pressure (86–106) kPa; chamber empty. |
| Applicable Test Standards | IEC 60068-2-78 Test Cab: Steady-State Damp Heat |
| Performance |
| Temperature Range | -30°C to +70°C |
| Temperature Fluctuation | ≤ ±0.5°C |
| Temperature Deviation | ±2.0°C |
| Temperature Uniformity | 2.0°C |
| Temperature Rise Time | +20°C → +85°C ≤ 20 min (no load) |
| Temperature Fall Time | +20°C → -40°C ≤ 60 min (no load) |
| Humidity Range (Humidity Type Only) | 
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| Relative Humidity Deviation | ±3%RH (＞75%RH, no load)
±5%RH (≤75%RH, no load) |
| Humidity Fluctuation | ±2.5%RH |
| Air Velocity (center of chamber) | 0.5–2.0 m/s (frequency adjustable).
All performance indicators must be met at air velocity ≤2.0 m/s. |
| Airflow direction | vertical downward |
| Working Heat Load (Heat Dissipation Capacity) | -40°C to +0°C: ≤2000 W +0°C to +85°C: ≤6000 W |
| Structural Features |
| Thermal Insulation Structure | Composite modular panels consisting of: Powder-coated galvanized steel (outer panel) → Thermal insulation material → SUS304 stainless steel (inner panel) Outer panel: A3 cold-rolled steel, thickness ≥1.0 mm, HOHUXI standard color Inner panel: SUS304, thickness ≥1.0 mm; floor with embossed anti-slip stainless steel Insulation thickness: ≥100 mm Floor load capacity: 1000 kg/m² (uniform load) Floor: SUS304 embossed anti-slip steel plate, thickness 2.5 mm |
| Air Conditioning Channel | Centrifugal fans: ≥4 units
Heater, evaporator (also for dehumidification), water inlet/outlet, dry-bulb sensor
Humidity type chamber additionally includes: humidifier, anti-dry-burn protection |
| Standard Configuration | Cable ports: φ100 mm × 2 (left side), with caps and silicone plugs Lighting: 60W/AC220V × 4, indicator tower light, buzzer, Pressure balance device |
| Door | Dual hinged double-leaf door Single-leaf: H2000 mm × W1200 mm Safety lock (openable from inside) Heated anti-condensation double-glazed viewing windows (W400 × H600 mm ×2) Heated door frame |
| Control Panel | Temperature & humidity display controller, over-temperature protector, emergency stop, run indicator, fault indicator, buzzer |
| Mechanical Compartment | Refrigeration system, drain/water system, fans, electrical control cabinet, humidification & water control system |
| Electrical Control Cabinet | Cooling fans, distribution board, sample power terminals, RS-485 interface, main power breaker |
| Heater | 316 stainless steel armored heater
Control method: SSR (solid-state relay) zero-crossing PWM |
| Humidification (Humidity Type Only) | Boiler-type steam humidification, 316 stainless steel heater
SSR PWM control
Water level control and dry-burn protection |
| Refrigeration System |
| Working Method | Compressor refrigeration system |
| Evaporator | Finned heat exchanger (also for dehumidification) |
| Condenser | Shell-and-tube or brazed plate heat exchanger |
| Expansion Device | Thermal expansion valve, capillary tube |
| Refrigeration Control | PLC automatically adjusts refrigeration conditions |
| Refrigerants | R404A, R23 (both with zero ozone depletion index) |
| Main Component Brands | Compressor | Bitzer (Germany, dual compressors) |
| | Refrigerant | DuPont/Honeywell (USA) |
| | Refrigeration Oil | American Arctic Bear/Honeywell |
| | Pressure Switch | Danfoss (Denmark) / SAGInoMIYA (Japan) |
| | Evaporator Pressure Regulato | Danfoss |
| | Dryer Filter | Danfoss / Emerson (USA) |
| | Expansion Valve | Danfoss / SPORLAN (USA) |
| | Solenoid Valve | SAGInoMIYA (Japan) / ODE (Germany) |
| | Oil Separator | Emerson |
| Electrical Control System |
| Display | 7-inch TFT true-color LCD, 800×480 resolution |
| Operation Modes | Program and constant value |
| Setting Method | Touch panel, Chinese/English menu |
| Program Capacity | 100 programs, each up to 10,000 steps, 9999 loops |
| Setting Range | Temperature: device range +5°C / –5°C extension
Humidity: 0–100%RH (humidity chamber) |
| Display Resolution | Temperature: 0.01°C
Time: 0.01 min
Humidity: 0.1%RH |
| Inputs | PT100 RTD, voltage, current (depending on configuration) |
| Communication | PC connection for curve display & data logging
Remote monitoring and control
Multi-chamber synchronization
RS-485, RS-232, Ethernet (choose one), USB 2.0 |
| Control Method | Temperature: anti-integral-saturation PID + auto-tuning
Humidity: anti-integral-saturation PID + auto-tuning |
| Curve Recording | Battery-backed RAM
Recording interval: 1 s –120 s
Maximum history: 720 days (at 2 min interval)
Data retention ≥10 years (without power) |
| Additional Functions | Fault alarm with cause & troubleshooting guide
Power failure recovery
Upper/Lower temp limit protection
Timer (auto start/stop)
Self-diagnosis |
| Temperature & Humidity Sensors | Temperature: PT100 RTD
Humidity: Electronic humidity sensor |
| Electrical Component Brands | Power Switch | CHNT |
| AC Contactor | Schneider (France) |
| Thermal Relay | Schneider |
| Phase Sequence Relay | Schneider |
| High/Low Temp Protector | Yatai |
| AC Relay | Schneider / Fuji (Japan) |
| SSR | Yangming |
| Water Supply System (Humidity Type Only) |
| Water Supply Method | Pump lifting |
| Water Tank | Hidden type |
| Safety Protection Devices |
| Refrigeration System | Compressor overpressure
Compressor motor overheating
Compressor motor overcurrent
Cooling water low pressure |
| Humidification System (Humidity Type Only) | Low water level warning
Anti-dry-burn protection |
| Test Chamber | Adjustable high/low temperature limiter
Thermal fuse in test space
Air channel over-temperature protection
Fan motor overcurrent |
| Other | Phase sequence & phase loss protection
Leakage protection
Load short-circuit protection |
| Other Configurations |
| Sample Power Terminals | Relay-controlled, AC220V, within 2A
Closed during operation; open during stop or fault |
| Additional Items | Two internal sockets (10A), resistant to -30°C without cracking |
| Cooling Method | Water-cooled system (manufacturer provides cooling tower, water pump, and installation) |
