There are two reasons why the SF red light flashes: the internal software of the module detects an external thermal resistance disconnection, or the input is out of range. Since the above detection is shared by the two input channels, the SF lamp must blink when only one channel is externally connected to the thermal resistor. The solution is to connect a 100 Ohm resistor to the empty channel in the same way as the used channel; or connect all the leads of the already connected thermal resistor to the empty channel one by one. Investment Casting, also known as lost wax casting, includes wax pressing, wax repairing, tree formation, paste, wax melting, casting metal liquid and post-treatment processes. Lost wax casting is the process of making a wax mold of the part to be cast, and then coating the wax mold with mud. After the clay mold is dried, melt the wax mold inside in hot water. Melt the wax mold out of the clay mold and then roast into pottery mold. Once roasted. Generally, a casting port is left when the mold is made, and then molten metal is poured into the pouring port. After cooling, the required parts are made. Investment Casting,Lost Wax Casting,Steel Investment Casting,Stainless Steel Investment Casting Tianhui Machine Co.,Ltd , https://www.thcastings.com