The invention relates to the field of
dew point
temperature measurement, and particularly relates to a chilled-mirror
dew-point
hygrometer capable of quickly measuring an extremely low
dew point. Thechilled-mirror dew-point
hygrometer comprises a gas
path system, a light
path system, a refrigerating
system and a
control system, wherein the gas
path system comprises a test cavity, a sampling pipeline and an auxiliary humidifying unit, the auxiliary humidifying unit comprises a humidifying pipeline and an
electromagnetic valve, and two ends of the humidifying pipeline are connected to two openings of the sampling pipeline; the light path
system comprises a transmitting
light source, a mirror surface and a photosensitive
receiver, the mirror surface is located in the test cavity, the transmitting
light source irradiates the mirror surface, and reflected light is received by the photosensitive
receiver; the refrigerating
system comprises a
semiconductor refrigerator and a compressor refrigerator for performing pre-
refrigeration treatment on the
semiconductor refrigerator, the cold end of the
semiconductor refrigerator is connected to the bottom of the mirror surface, and the hot end of the semiconductor refrigerator is mounted on an
evaporator of the compressor refrigerator; and the
control system is electrically connected with the gas path system, the light path system and the refrigerating system. The chilled-mirror dew-point
hygrometer can measure an extremely low
dew point, and is high in measurement speed, high in accuracy and high in stability.