| 摘要 |
<p>1357217 Thermocouples BEST PRODUCTS Ltd 3 July 1972 [9 July 1971 19 Nov 1971] 32430/71 and 53924/71 Heading H1K A flat strip of metal comprising substantially parallel limbs connected together alternately at opposite ends has its limbs alternately coated with a higher conductivity metal so as to define two sets of thermojunctions disposed respectively at opposite ends of the limbs. Such an arrangement may be formed from a thin sheet of epoxy-backed constantan bearing parallel strips of copper by removal of material as by etching through photoresist masking. The copper may be deposited in strips or an overall coating reduced to strips as by masked etching. When using unbacked sheet one entire face is plated with copper, after which material is removed in a two step process to leave the completed sinuous form attached at its junctions to a supporting frame. The steps, which respectively involve removal of copper from areas where it is not required, and removal of the entire thickness of metal, may be performed in either order. If a laser is used to remove material only one step is required, the beam having its intensity modulated as it scans the entire sheet so as to remove the entire thickness, only the copper or nothing at a given location. The two sets of junction may lie on parallel lines or on concentric circles and a respective heater wire, possibly coated with glass, bonded to each set of junctions or one wire bonded to half of the junctions of each set and the other to the other half. The assembly may be mounted in a heat sink formed by two channel members bolted together with the centres of the limbs clamped between ridges on the channel bases from which they are insulated by mica strips, and placed in an evacuated enclosure.</p> |
