Temperature control devices in salt spray test chambers regulate temperature variations in the working environment. These devices utilize physical changes within their mechanisms to trigger specific responses, such as opening or closing circuits, thereby achieving automatic temperature control. Below are the five common types of temperature controllers used in these chambers:

1. Pressure-Type Temperature Controller
Application: Commonly used in refrigeration and heating equipment.
Working Principle: A sealed temperature-sensitive bulb and capillary tube convert temperature changes into pressure or volume variations. When the temperature reaches the set value, the elastic component and quick-action mechanism automatically open or close the contacts, achieving temperature control.

2. Snap-Action Temperature Controller
Working Principle: Uses a pre-calibrated bimetallic strip as a thermal sensing element.
Operation: When the temperature rises, heat is transferred to the bimetallic strip. Once the set temperature is reached, the strip deforms, causing the contacts to open or close instantly. When the temperature drops to the reset point, the strip returns to its original shape, restoring the circuit connection.
3. Liquid Expansion Temperature Controller
Application: Widely used in home appliances and refrigeration systems.
Working Principle: The temperature change of the controlled object causes thermal expansion or contraction of the fluid inside the sensor. This volume change is transmitted to a connected bellows, which expands or contracts to trigger the control mechanism.
4. Digital Temperature Controller
Advantages: High sensitivity and precision.
Working Principle: Uses NTC thermistors or thermocouples to detect temperature changes, converting them into corresponding voltage or current signals. A microcontroller processes these signals, displays the temperature digitally, and executes control actions accordingly.
5. Electronic Temperature Controller
Features: Compact, stable, and commonly used in household air conditioners.
Working Principle: Relies on resistance-based temperature sensing using materials like tungsten wire, copper wire, or thermistors. The resistance changes with temperature, allowing the device to measure and regulate heat accurately.
Conclusion
Different temperature control devices offer unique advantages depending on the application. Pressure-type and snap-action controllers are mechanical and reliable, while digital and electronic controllers provide higher precision and automation. The choice depends on factors like accuracy requirements, environmental conditions, and cost considerations.

For professional salt spray test chambers, selecting the right temperature control system ensures stable performance and accurate test results. Manufacturers like Linpin Instruments customize solutions based on specific testing needs, balancing performance and budget for optimal efficiency.