Air flow/mass sensor (MAF)

Q. What voltage did you get when you first powered up the sensor without passing air over the sensor?
A. 1.10 V

Q.How did the voltage change when air was passed over the sensor?
A. When air passed over the sensor, the voltage increases.

Q. Are your result within the manufacturer's specifications, why or why not?
A. The value of voltage depends upon the pressure of the air over the sensor. we did not know the what pressure we blown over the sensor so I cann't say that whether it matches with the specifications or not.

Q. Explain the internal operation of this sensor

                                            (Lesson 2, Sensors: Theory class notes)

A. When the engine revs up, the influx of air enters MAF and the voltage rises up at the terminals. The sensor in the box is a simple wheat-stone bridge. When the engine revs up, the fulx of air entered into the big hole of the box. This flux cools the thermistor and lower the resistance of the thermistor. This increases the voltage at A as the more voltage is dropped across anther resistor. This increased voltage goes to non inverting side of the op-amps hence increases the out put which switch on the transistor and thus the current start flowing down toward the thermistor and plantinum wire junction. This increase in current makes the thermistor back to the previous temperature. The current also makes the platinum wire hot and give the increased signal to ECU.