The causes of temperature sensor failures are both simple and complex, and specific problems must be analyzed. Based on more than a decade of production and work experience, the sensor expert network provides a simple analysis as follows.
1. Clearly confirm that the temperature sensor is faulty. Seemingly a nonsense, it is actually very important. When many technicians encounter problems on site, they always think that the temperature sensor is broken at the first time, and assume that it is the temperature sensor that is broken. When there was a malfunction on site, the first thing that came to mind was the temperature sensor, indicating that the direction and approach were correct. Dealing with any problem had to go from simple to complex, but assuming it was too subjective and arbitrary, which was not conducive to quickly identifying the problem. How to determine if the temperature sensor is broken? It's simple - check what you think is bad, or simply replace it with a new one.
2. Check the wiring. The system faults other than sensors are not within the scope of this article's analysis (can be found on the Sensor Expert Network). Therefore, to clarify that the sensor is faulty, the next step is to check the connection wires, including the connection wires between the sensor and the instrument, the collection module, the sensor and the sensor, and the wires of the sensor itself. In summary, it is necessary to determine and eliminate the wiring faults caused by loose connections, virtual connections, short circuits, and other reasons, in order to reduce the cost of maintenance and repair.
3. Determine the type of temperature sensor. This is a common low-level mistake. There are many types of temperature sensors, including resistance type, analog type, digital type, etc. As a technician, you need to know how to make a judgment first. Using a multimeter to measure the resistance of a resistive type can immediately determine its quality, positive temperature, negative temperature, resistance value, etc; For analog models, you can use an oscilloscope to observe the amplitude and waveform of voltage or current output, and then make further judgments; Digital temperature sensors are a bit troublesome because they usually have a small integrated circuit inside and need to communicate with a microcontroller to determine. You can use your own microcontroller for individual testing, or use the manufacturer's or commonly used instruments for testing. Digital temperature sensors are generally not allowed to be measured directly with a multimeter, because excessive voltage or direct burning of the "chip" can lead to new circuit faults, making it impossible to determine the true cause of the fault.
In order to ensure the normal operation of these components and equipment with temperature sensors, we must learn the causes of temperature sensor failures when maintaining these devices.