Meteorological instruments are specialized equipment used in meteorological services such as weather forecasting and meteorological monitoring. They can be classified into two main categories: ground meteorological observation instruments and upper-air meteorological detection instruments. [1] They mainly include automatic weather stations, automatic rain gauges, anemometers, wind vanes, Stevenson screens, temperature and humidity recorders, sensors, wind vanes, wind speed alarms, wind energy anemometers, meteorological center software, GPRS wireless transmission modules, etc.
The principle is the same as that of a single-tube thermometer, but the structure is slightly different. It uses a capillary tube connected to a circular sensing part, and the capillary tube is then fixed to the scale plate. The sensing part is connected to an outer tube, and the outer tube is filled with dry air so that water vapor does not condense on the tube wall due to temperature changes, affecting the reading. The upper end of the outer tube is then sealed. The advantage of a double-tube thermometer is that the scale plate does not come into contact with the outside humid air, so the scale is not blurred, and the dry air inside can also isolate the influence of radiant heat.
