| 摘要 |
The resistance thermometer element is made by forming a serpentine pattern 16,18,20 of a thin film of a metal such as platinum deposited on a substrate 10. The deposited metal has a bulk temperature coefficient of resistance (TCR) substantially greater than the desired TCR which is established by controlling the thickness of the film to the correct value in a range of thicknesses where TCR changes relatively rapidly with thickness, eg the range 0.05 to 0.8 microns for platinum. The required thickness may be established by deposition at a control rate for a controlled time or by over deposition followed by reduction in thickness by etching. The calibration resistance at the ice point is then independently established by selective removal of shorting links in parts 22, 24, 26, 28 of the pattern. |
