As one of the important components in the fuel injection system, the manifold absolute pressure sensor is usually used by the engine control module (ECM) to monitor the intake manifold pressure information in real time, then calculate the fuel injection to obtain the best air-fuel ratio. In view of the need to maintain stability in high-temperature environments, NTC thermistor is added to the manifold absolute pressure sensor to avoid engine damage due to temperature errors in judgment.
NTC thermistor is generally installed at the air inlet of the manifold absolute pressure sensor to measure the air temperature of the intake manifold in real time. After collecting the temperature of intake air, the thermistor is first carried out with the set comparison temperature value, then combined with the internal signal conditioning module and Micro-electro Mechanical System (MEMS) chip, through calculation, the data is converted into the corresponding pressure information, helping the manifold absolute pressure sensor to output the voltage signal for the engine control module accurately to determine in real time when it should turn on the engine under different load conditions. Therefore, with the assistance of NTC thermistor, the measurement of the manifold absolute pressure sensor is more accurate, which can effectively improve the efficiency of the combustion process of engine fuel, thereby reducing exhaust emissions. Moreover, the pressure data obtained by the manifold absolute pressure sensor can also be used to determine whether the exhaust gas re-circulation (EGR) valve is faulty or leaking.
Since the start-up time of engine is very short, the fast response of NTC thermistor can also reduce the measurement time and data transmission time of the manifold absolute pressure sensor. Moreover, the temperature of the engine is high when operating, and the NTC thermistor needs to withstand high temperature to prevent technical deviations. VT series automotive NTC thermistor of EXSENSE Electronics Technology Co., Ltd., its wide operating temperature range (-40~150℃, which can up to 200℃ in a short time), can well meet the working needs of the manifold absolute pressure sensor, and plays a vital role in its work.