Temperature controls regulate and maintain a desired setpoint temperature for commercial or industrial HVAC and refrigeration equipment. Electronic temperature controls regulate HVAC temperatures by taking highly accurate readings from connected sensors and activating the HVAC system when setpoint temperatures are reached. Mechanical temperature controls measure and react to temperature swings using changes in physical objects such as a bi-metal strip or a bulb containing mercury. They are simpler than electronic controls but are less accurate and take much more time to respond to temperature changes.