Temperature rise curve can directly reflect the characteristic performance of thermocouple

For temperature rise curve have a concept? Temperature rise is actually in order to test the product, the temperature change at all time points, so very easy to understand, we should can be very direct. So how can we more accurately draw a thermocouple temperature curve of this product? In fact as long as according to our three cheong instrument engineer practice can get a precise temperature curve.

wanted to test the service life of the thermocouple, stability features, usually will test its important components ( IC chip, IGBT, etc. ) The temperature rise, put equipment under test at a specific temperature ( Such as room temperature or a specific temperature) Stable running, record its element is higher than the rise of temperature of the ambient temperature, by determining the product parts whether meet the requirements of standard value of temperature rise, to verify the reliability of the product and the rationality of the design of products.

the purpose of temperature rise is to gather all the test points to the temperature change of the situation: to observe the changes in temperature curve is reasonable, such as the temperature rise is within the scope of the permit; If there are abnormal, stop the test, save the existing data, review and analysis. As shown in figure 1 is the temperature records. Figure 1

temperature rise curve

flow after conductor current heating, with the passage of time, the surface temperature of the conductor continually rise until stability. Stability judgment conditions are in all test points in one hour before and after the test interval temperature less than 2 K, measured the temperature and the test of any test point at this time the last 1/4 cycle average environment temperature difference is called a temperature rise, unit for K.

how can record the rise of temperature of the thermocouple operation? Usually there are two kinds of test methods:

1, the traditional test methods:

use normal for collection after working temperature being measured, artificial use EXCEL to do a lot of data operation, work temperature - being tested Fixed value at room temperature; But the traditional method to spend a lot of artificial cost, test results is not accurate.

2, new test method for:

by Delta operation methods will input end ( Working temperature) to be tested With the benchmark channel ( Test environment temperature, such as room temperature) Measured value difference, as the measured value of the channel. In the temperature measurement, based on room temperature, easy to measure and the difference between the room temperature. As shown in figure 2.

as figure 2 operation model under the environment of room temperature 25 ℃, power supply temperature rise tests, namely on the surface of all key components, such as IGBT, inductors, such as semiconductor device or magnetic device, usually using a thermocouple ( R, S, B, E, J, K, T, N) Wiring.

thermocouple solder joints: thermocouple probe in the position to be tested, on glue;

thermocouple walk line: try to tidy the inside of the machine wire and tied up with high temperature tape, walked trough or wire groove;

thermocouple wire, not from the into the outlet, or other nervous QuanChu.

when there are two different conductors or semiconductor A and B to form A loop, its both ends are connected, as long as the temperature of the two nodes is different, one end of the temperature T, called end or hot end work, on the other side temperature T0, known as the free end, Also known as the reference side) Or the cold end, the circuit will generate an electromotive force, the direction and size of the electromotive force is related to the conductor material and the temperature of the two contact. This phenomenon is called & other; Thermoelectric effect & throughout; , two conductors circuit called & other; Thermocouple & throughout; , the two conductor is called & other; Hot electrode & throughout; , produces electromotive force is called & other; Thermoelectric emfs & throughout; 。 Through this model to determine the temperature rise process.

when measuring sites scattered, measurement and field data recorder which can be installed separately to avoid long distance connection signal lines. Many sets of cascade, DM100 data acquisition recorder can be extended to a maximum of 200 acquisition channel, strong expansibility, suitable for multi-channel data acquisition record.

through the above steps is introduced in detail, I think we must have the thermocouple temperature rise curve have a very deep understanding of the measurement. We three chang instrument through long-term accumulation of experience, in product technology is mature, everybody if there are any questions, you can feel free to contact us.