HCDAR-8X series radar level sensor is one kind of level measuring instrument which uses FMCW ( Frequency Modulated Continuous Wave ) special millimeter wave technology , the working frequency is 76-81Ghz. The signal output has options : 2 wires 4-20mA, 4 wires 4-20mA or RS485.  The max range can reach 120m, and the blind zone of 8cm. The antenna beam angle is about 3°,the outstanding performance makes it is workable for the accurate measurement of liquids, solids, and powder materials. 

The radar level sensor emits linear frequency modulated pulse signal, and captures the echo wave reflected by the barriers on the path of wave spreading. It combines this two signals by “mixer” , and get an intermediate frequency signal (IF), we will get the distance what we want by process this signal and calculation.