The so-called Environmental Detection Sensor, which is a very sensitive for the temperature of the resistor. And this resistor in the temperature changes when its resistance will also change accordingly.
Currently on the market more types of Environmental Detection Sensors, if the temperature sensor manufacturers in accordance with its structure and shape can be roughly divided into spherical, rod-shaped, tubular, round, round and so on. And then we are in accordance with the different heating methods can be divided into direct thermal environment detection sensors and bypass thermal detection sensors. At the same time in accordance with the working temperature range can be divided into room temperature, high temperature, ultra-low temperature thermistor. According to the temperature coefficient can be divided into positive temperature coefficient thermistor and negative temperature coefficient of Environmental Detection Sensor.
Today we simply talk about the detection of Environmental Detection Sensor failure:
(1) First of all, we look at the appearance of the Environmental Detection Sensor. Potentiometer or Environmental Detection Sensor must be marked clearly, the solder plate or pin without corrosion, rotary shaft rotation flexibility, elastic appropriate, feel when the rotation is smooth, and no mechanical noise and jitter phenomenon.
(2) the use of hand gently shake the potentiometer or Environmental Detection Sensor pin, there should be no loose phenomenon.
(3) The center pin of the potentiometer or the Environmental Detection Sensor is connected to its internal movable contact. We use the multimeter of the two table pen, respectively, to connect the center pin and the rest of any pin, and then slowly rotate the shaft handle, the table pointer need to move accordingly, if the pointer has jump, drop the phenomenon, then the description The movable contact and the resistor are in poor contact.
(4) will be multimeter resistance block to the appropriate range, and then we are in the ohm zero, and finally the use of two table pen (regardless of positive and negative) and resistors are connected at both ends of the pin, so that can measure the actual Of the resistance value. Finally, the test value and the nominal value of the resistor to check, which can be a good judge whether the potentiometer or Environmental Detection Sensor is intact. If the multimeter pointer is immobile, then it means that the internal resistor and disconnected.
Currently the most widely used is the negative temperature coefficient of Environmental Detection Sensors, but also can be divided into temperature measurement, regulator type, ordinary type.
In general, the nominal value of the environmental inspection sensor is the resistance value at an ambient temperature of 25 ° C. When using a multimeter to measure its resistance, it does not necessarily match the nominal resistance. Here we simply use a positive temperature coefficient of Environmental Detection Sensor as an example, simply talk about its characteristics, the positive temperature coefficient of Environmental Detection Sensor is also called PTC thermistor, the resistance of such resistors when the resistance value will also be Then the increase in resistance and temperature changes are proportional to the relationship, but the temperature of the resistor exceeds a fixed value, its resistance will increase dramatically, a file to increase to the maximum Value, then the resistance value will slowly increase with the temperature began to decline.
As an important core component of the Environmental Detection Sensor kit, how to ensure the quality of the environmental inspection sensor, how to reduce the damage caused by the sensor caused by the associated aftermarket costs, these problems are as a professional controller and sensor manufacturers for different applications , The appropriate choice of supporting products, an important factor. Sometimes our customers will also care about our sensor response time, this parameter is considered from the sensor that is, when the temperature changes, the Environmental Detection Sensor can sense the resistance change time. Simply talk about the response time of the sensor, for our users, the basic meaning is not, it is with the controller to talk about "response time" is more important. And from the perspective of solving practical problems customers consider the environmental testing of some of the necessary testing to ensure the quality of its role. These reliability tests are quite important.