Mechanism & Circuit structure of electric contactor. Thermometers with contactor have made possible the automation of temperature control and increased the safety of energy consuming. Electric contact acts as a switch control that follows the dial value on the thermometer. The pointer can be adjusted to send signals for the contactor to switch ON or OFF. Thermometers equipped with this optional feature will turn alarm signals ''ON'' or ''OFF'' automaticaly when the adjusted value is reached. And where appropriate relays are incorporated in the installation circuit, contacts will turn ''ON'' or ''OFF'' electric motors, heaters, valves, etc.