When it comes to sensors for diesel and gas engines each one plays an important role. The computer is the brain of an industrial engine control system and the sensors communicate any problems to the computer. Some sensors have more influence on engine performance than others. These include the coolant temperature sensor, oxygen sensor, throttle position sensor, and manifold absolute pressure sensor.
The temperature sensor is often referred to as the master sensor because the computer uses its input to regulate many other functions. A temperature sensor helps the computer determine if the fuel needs to be made richer or leaner. It also helps the computer make necessary adjustments for speed while the engine is in operation. Usually located on the head or intake manifold, coolant sensors screw into the water jacket. These sensors come in two basic varieties. There are variable resistor sensors called thermistors because their electrical resistance changes with temperature, and on/off switches, which work like a conventional thermostat by closing or opening at a preset temperature. A variable resistor coolant sensor provides the computer with a more accurate indication of actual engine temperature than a simple temperature switch.temperature sensor
The oxygen sensor is used to measure the amount of unburned oxygen in the exhaust. This information is used by the computer to indicate how rich or lean the fuel mixture is. The computer can then use this information to keep it properly balanced. The throttle position sensor is used with feedback carburetion and electronic fuel injection to inform the computer about the rate of throttle opening and relative throttle position. The throttle position sensor can be mounted externally on the throttle shaft or internally in the carburetor. The throttle position sensor is a variable resistor. It changes the resistance as the throttle opens. When the computer is signaled that the throttle is open, the computer enriches the fuel mixture to maintain the proper air to fuel ratio. The function of the manifold absolute pressure sensor is to sense air pressure or vacuum in the intake manifold. The computer then uses this input as an indicator of the engine load when adjusting the air/fuel mixture and spark timing. This allows for better fuel economy.
Using quality, durable sensors can reduce the amount of fuel an engine requires. Using sensors developed for specialized applications can also increase safety and reliability. Using sensors built to the specifications of an engine will increase its longevity and ensure better performance.