According to the quality of the heating core circulating in the mall, the heating core is divided into A-grade, B-grade and C-grade unqualified products in detail, and the detailed classification specifications are as follows (the temperature error is compared to the white light A1321 with a sensor resistance of 50 ohms):
Class A The sensor contains platinum material, the sensor resistance is 45-55 ohms, the temperature error is +15°C, and the linear region is 250--530°C.
Class B sensor does not contain platinum material, sensor resistance value 54-57 ohm product, linear region 250--430 °C, temperature +50 °C, temperature above 430 °C prone to temperature runaway.
Class C sensor does not contain platinum material, temperature difference below 54 ohms, 57 ohms above 50 °C-180 product linearity difference, easy to appear high temperature loss control, incineration of soldering station electronic parts.
Note: linearity is the corresponding value of the temperature rise and the sensor resistance, generally the greater the linearity, the better, the larger the temperature that can be controlled, the stronger
The first point: it is also a very important and very simple difference - the resistance value of the heating core; A1321 has a total of 4 electrodes, of which the upper two electrodes (the color of the insulated tube is blue) are temperature sensing resistance wires, which are used to measure the temperature of the heating core; The two electrodes below (the color of the insulated tube is red) are heating electrodes that are used to provide the power supply required to heat the heating core. The temperature sensing wire resistance of the A grade heating core is within the scale of 45-55 ohms, that is, the scale of the temperature sensing resistance wire Z assembly of the heating core imported from Japan; Domestic heating core below grade A for controlling the temperature, the temperature resistance is controlled within the scale of 50-60 ohms, the detailed reason is that the resistance of the heating core below class A with the temperature increase value is not enough, it is necessary to add 5 ohms to improve, but it is still a simple phenomenon of high temperature runaway and poor linearity. The A-grade heating core is added with platinum components to the temperature sensing line, so that its electrical parameters are consistent with 99% of the imported heating core.
The second point: the robustness of the solder joint; In the installation of the machine often encounter the problem of heating core electrode drop, if it falls directly is a good fate, but if the soldering station goes out to the customer electrode drop will form a great quality accident, and may lose the customer, so this is a very important reference parameter target. The detailed operation test and Z low specification of this goal is to put the electrode wire at a 90-degree angle to the heating mandrel body and apply an external force of 3kg to pull it without falling. Part of the A-grade heating core can reach more than 8kg, and the tensile force will not fall.
The third point: linearity and temperature control of the product; The quality of linearity is an important specification for evaluating the quality of a soldering station, and the quality of the linearity of the soldering station depends 100% on the quality of the heating core. The general heating core is calibrated at 350 °C, and then the scale of 20 °C is gradually increased or lowered, and the temperature of the soldering iron tip is measured by a thermometer during the application process (recommended to be measured by the Japanese white light 191 thermometer), the quality of the deviation within the scale of +15 °C is better, and the quality of 15-50 °C exceeds this scale, and the quality above 50 °C is inferior.
According to the sampling test of the shopping mall, the linearity and performance of the heating core of platinum-containing materials in the scale of 45-55 ohms are similar to those of Japanese products, (error 0--+ 15 °C) 350-530 °C temperature. It is difficult to achieve consistency in the linearity of the heating core without platinum materials, so it is difficult to be consistent in the temperature debugging of the machine by simply forming a machine, and the temperature of the machine is high or low after the new heating core is installed.
The fourth point: high temperature temperature control ability, the temperature of the soldering station is set to 480 °C (the same is also necessary to select the temperature sensing wire resistance value in the scale of 45-50 ohms), if the soldering station has been displayed in heating, but the temperature has not reached 480 °C, then this is the temperature is out of control, which is a quite serious problem. The main situation is not that the soldering station is heated less than 480 °C, but the temperature has even greatly exceeded 480 °C, but the signal of the heating core to the soldering station is still not enough temperature, so that the continuous high current forms a transformer or other electronic components damaged, bringing great losses to customers.
