Contactless temperature measurement of surface of object inside hot air dryers and heat treatment plants

摘要

The temp. measurement involves two temperature sensors (1,2) disposed inside the hot air dryer. The sensors have equal conductive and convective properties but differing emission factors. The object to be measured (4) emits heat rays which are picked up by the first two sensors.A third sensor (3), protected by a tube (7) from the heat rays, only measures the air temperature in the dryer. By comparing the different measurements from each sensor, the temperature of the heat rays from the object can be established using an equation which relates the measurement quantities.