| 摘要 |
<p>The instrument has a mirror, a heating device, a cooling source and a housing with a temperature sensor. The housing (3) contains the temperature sensor (4), and has the heating device (5) on at least one side, e.g. the top, on which the mirror (9) and a set of electrical contacts (8) are mounted. The heating device may be a semiconductor plate (6) with a diode junction (7) or a layer of electrically resistant material (11) separated from the housing by an insulating layer (10). The instrument can be provided with a circuit to maintain constant condensation on the mirror, whereby light from a source (12) is reflected from the mirror and detected by a photocell (13) whose output signal controls the heating device.</p> |
