Apply some new silicone grease, and see if the CPU fan speed is lower than before, if it is, consider replacing the fan. There may also be a sensor problem, so you can turn the alarm temperature up! If the temperature of the measuring medium is 70 to 80 ° C, it is only necessary to add a radiator at the connection between the pressure sensor or the pressure gauge and the pressure collection, so that the temperature can be properly lowered a little, so that the medium can be indirectly contacted with the instrument after heat dissipation through the radiator.
< br >
If the temperature of the measuring medium exceeds 100 ° C and the maximum reaches 200 ° C, we need to install a condensing ring at the pressure inlet and then add a radiator, so that the temperature is very low when the medium is cooled by the condensing ring, and then the heat dissipation through the radiator is in indirect contact with the pressure sensor.
< br >
In the use of ultra-high temperature measurement places, the pressure tube can be extended and then connected to the pressure sensor, and the heat sink can also be installed after the capillary tube to achieve the effect of media cooling.
< br >
The above are several pressure sensor installation methods for several medium temperatures to pass the high temperature, which is different from adding an isolation diaphragm. The pressure sensor or pressure gauge is equipped with an isolation diaphragm, that is, a diaphragm pressure gauge and a diaphragm pressure sensor, which is designed for a medium that is easily blocked and erosive, so that the pressure of the medium acts on the diaphragm, rather than the indirect contact with the pressure sensor.
< br >
Therefore, the installation of the sensor is not only related to its measurement accuracy, but also related to its service life, so it is necessary to pay attention to its installation method at low temperatures.
1. First check the vehicle cooling system, cold car check whether the antifreeze liquid level is normal, check whether the antifreeze is normal.
2. Use a special computer to read the engine water temperature value and the water outlet temperature of the water tank to see whether the engine water temperature rises and the water outlet temperature of the water tank changes.
3. Remove the sensor for inspection, the measurement resistance is almost the same in the same water temperature, and the resistance changes in the same water temperature (the sensor is not abnormal).
4. Then remove the water pump and thermostat to check (the water pump is a mechanical water pump) and check how the water pump shaft is connected.
5. Heat the thermostat in water, observe the opening state, and check whether the thermostat opens when it is heated to 100℃. Replace thermostat if not turned on.
6. Use a dedicated computer to read data samples. When the vehicle alarms, the temperature of the engine temperature sensor and the outlet temperature of the water tank do not exceed 100℃, the engine temperature is 90℃, and the water temperature changes steadily. The oil temperature changes too fast or even more than 150 ° C, indicating that the oil temperature sensor is too high to cause the motor temperature is too high.
7. Finally, check the oil temperature.
Temperature sensor to pt100 thermal resistance as an example, first send the temperature signal to the temperature transmitter, output 4ma- 20ma current, and then send the signal to the analog processing module, the internal program to be set, through pid operation (that is, proportional, differential, integral), through the analog module output to the controller, you can control the temperature.
Temperature sensor to pt100 thermal resistance as an example, first send the temperature signal to the temperature transmitter, output 4ma- 20ma current, and then send the signal to the analog processing module, the internal program to be set, through pid operation (that is, proportional, differential, integral), through the analog module output to the controller, you can control the temperature.
If the voltage is below 4.9 volts, test the engine coolant temperature sensor signal circuit for excessive resistance or open circuit.
2. If the voltage is higher than 5.2 volts, test whether the signal circuit of the engine coolant temperature sensor is short circuited to the voltage.
3. If the engine coolant temperature sensor signal circuit test results are normal, and the voltage is still not within a reasonable range, the engine control module has a problem and needs to be replaced. Extended data: The resistance detection of cooling water temperature sensor can be divided into two methods: vehicle detection method and single inspection method. a. The car inspection method. Set the ignition switch to the OFF position, remove the cooling water temperature sensor wire connector, and test the resistance value between the THW and E2 terminals of the sensor with a digital high-impedance multimeter in Ω gear. Its resistance value is inversely proportional to the temperature. b. Single piece inspection method. Unplug the coolant temperature sensor harness, then remove the coolant temperature sensor from the engine; Place the coolant temperature sensor in the water of the beaker and heat the water in the cup; At the same time, use a multimeter to measure the resistance between the two terminals of the water temperature sensor under different water temperature conditions and compare the measured value with the standard value. If the value does not meet the standard, replace the water temperature sensor.
The best solution is to replace the sensor with a new one