Type II — High-Pressure第 128 / 240 题
During evacuation of a Type II system, a technician wants to confirm the system has reached a deep, dry vacuum. Which instrument gives the precise reading needed?
a.A micron (vacuum) gauge
b.A standard compound gauge on the manifold
c.A superheat thermometer
d.A clamp-on ammeter
解析
A micron gauge (electronic vacuum gauge) reads the very low absolute pressures needed to confirm a deep, dry vacuum, often around 500 microns for good dehydration. A standard compound gauge is not precise enough in deep vacuum. Superheat thermometers and ammeters measure entirely different parameters.
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