The water-cooling two-zone thermal shock test chamber is a specialized environmental testing equipment designed to simulate extreme and rapid temperature changes (thermal shock) on test samples. Unlike air-cooled models, it adopts a water-cooling system for heat dissipation, making it ideal for high-heat-load scenarios and continuous long-term operations. Its "two-zone" structure—consisting of independent high-temperature and low-temperature zones—enables efficient, cyclic thermal shock testing to evaluate a product’s resistance to temperature fluctuations.
1. Core Definition & Working Principle
Key Concept
This chamber is engineered to expose test samples to abrupt transitions between two pre-set temperature environments (high and low) repeatedly. The "water-cooling" feature specifically targets the heat generated by the high-temperature zone and refrigeration system, ensuring stable temperature control and avoiding overheating. The "two-zone" design separates high and low-temperature spaces, eliminating the need for a single chamber to switch temperatures (a limitation of three-zone models), thus optimizing test efficiency.
Working Principle
The test process follows a cyclic, automated workflow, typically divided into 5 stages:
Preheating/Pre-cooling: The high-temperature zone (e.g., +150°C) is heated by heaters, while the low-temperature zone (e.g., -60°C) is cooled by a refrigeration system (usually a cascade refrigeration cycle for ultra-low temps). The water-cooling system simultaneously dissipates heat from the high-temperature zone’s heating elements and the refrigeration system’s condenser.
Sample Loading: The test sample is placed in a transfer mechanism (pnumatic-driven tray or elevator) located between the two zones.
High-Temp Exposure: The transfer mechanism moves the sample into the high-temperature zone, where it is held for a pre-set "soak time" (to ensure the sample’s core reaches the zone temperature).
Rapid Transfer & Low-Temp Exposure: After high-temp soaking, the transfer mechanism moves the sample to the low-temperature zone in <10 seconds (a critical parameter for "thermal shock"). The sample is then held for another soak time.
Cycle & End: Steps 3–4 repeat for the set number of cycles (e.g., 100, 500 cycles). After testing, the chamber alerts the user, and the sample is removed for performance analysis (e.g., checking for cracks, material deformation, or functional failures).
2. Core Components & Their Functions
Each component works in tandem to ensure precise temperature control, rapid transfer, and stable operation. The table below details key parts:
Component
Function
High-Temperature Zone
- Contains heaters (e.g., stainless steel heating tubes) and temperature sensors.
- Maintains constant high temperatures (typical range: +60°C to +200°C,).
Low-Temperature Zone
- Equipped with a refrigeration system (cascade type for -80°C to -40°C) and evaporators.
- Maintains stable low temperatures without frost buildup (aided by defrosting modules).
Water-Cooling System
- Includes a water tank, circulating pump, cooling coil, and water filter.
- Dissipates heat from the high-temperature zone and refrigeration condenser to prevent overheating.
- Requires clean, low-hardness water (to avoid scale buildup in coils).
Transfer Mechanism
- Motor-driven tray/elevator with high-speed (≤10s) transfer capability.
- Ensures the sample moves smoothly between zones to avoid mechanical damage.
Low-temperature zone: -80°C ~ -40°C (min -100°C for specialized models)
Thermal Shock Rate
Temperature transition time: ≤10 seconds (sample core temp change)
Soak Time
0 ~ 9999 minutes (adjustable per standard)
Cycle Count
0 ~ 9999 cycles (automatic stop after completion)
Water-Cooling Requirement
Inlet water temperature: ≤32°C
Inlet water pressure: 0.2 ~ 0.5 MPa
Water flow rate: 15 ~ 50 L/min (varies by chamber size)
Chamber Volume
Small: 50 ~ 200 L (benchtop)
Medium: 200 ~ 500 L
Large: 500 ~ 2000 L (industrial)
Temperature Uniformity
±2°C (high-temperature zone)
±3°C (low-temperature zone)
Temperature Accuracy
±0.5°C ~ ±1°C
4. Advantages of Water-Cooling Design (vs. Air-Cooling)
The water-cooling system is a critical advantage over air-cooled two-zone chambers, especially for demanding applications:
Higher Heat Dissipation Efficiency: Water has a higher specific heat capacity than air, making it more effective at removing heat from the high-temperature zone and refrigeration system. This ensures stable temperature control even during long-term (e.g., 24/7) testing.
Lower Ambient Heat Impact: Air-cooled chambers release heat into the lab environment, raising room temperature. Water-cooled models discharge heat via circulating water (e.g., to a cooling tower), keeping the lab cool and avoiding interference with other equipment.
Suitable for High-Temp Tests: For high-temperature zones above +200°C, air-cooling may struggle to dissipate heat, leading to temperature drift. Water-cooling handles high heat loads reliably.
Quieter Operation: Water-cooled systems have fewer noisy fans (common in air-cooled models), reducing lab noise pollution.
5. Applications
This chamber is widely used across industries to test products that encounter rapid temperature changes in real-world use. Key application areas include:
Electronics & Semiconductors: Testing chips, circuit boards, capacitors, and LEDs (to simulate temperature shocks during transportation or outdoor use, e.g., from cold nights to hot days).
Automotive: Evaluating auto parts like sensors, batteries, connectors, and headlights (to withstand under-hood heat and cold winter conditions).
Aerospace: Testing avionics, satellite components, and engine parts (to simulate extreme temperature shifts in high-altitude or space environments).
Materials Science: Assessing the thermal shock resistance of metals, ceramics, glass, and composites (e.g., checking for cracks in smartphone glass or industrial ceramics).
Pharmaceuticals & Packaging: Testing drug packaging (e.g., vials, blister packs) to ensure seal integrity and drug stability under temperature fluctuations during shipping.
6. Standards Compliance
To ensure test validity, the chamber is designed to meet international and industry standards, including:
IEC 60068-2-14 (Environmental testing – Part 2-14: Tests – Test N: Temperature change)
MIL-STD-883H (Test Method 1010.8: Thermal shock)
JIS C 0025 (Environmental testing for electronic equipment – Thermal shock test)
ASTM D1148 (Standard Test Method for Thermal Shock Resistance of Glass Containers)
7. Maintenance & Precautions
To extend the chamber’s lifespan and ensure test accuracy, regular maintenance and proper operation are essential:
Water-Cooling System: Replace filter elements monthly; use deionized or softened water to prevent scale (scale can block coils and reduce cooling efficiency). Drain and clean the water tank quarterly.
Temperature Zones: Clean the high-temperature zone’s heaters (remove dust) and low-temperature zone’s evaporators (defrost regularly to avoid frost buildup) every 6 months.
Transfer Mechanism: Lubricate moving parts (e.g., rails, motors) quarterly to ensure smooth, fast transfers.
Safety: Ensure the chamber is grounded; do not overload the sample tray (exceeding weight limits can damage the transfer mechanism); stop testing immediately if water leaks or temperature alarms trigger.
In summary, the water-cooling two-zone thermal shock test chamber is a high-performance tool for evaluating product reliability under extreme temperature changes. Its water-cooling efficiency, two-zone design, and compliance with global standards make it indispensable for industries where thermal stability is critical.
