| The TDR-2000 two-wire guided microwave level transmitter uses the TDR (Time Domain Reflectometry) principle. The instrument sends low power nanosecond-wide pulses along an electrically conductive cable with a known propagation speed (the speed of light). As the pulse reaches the surface of the medium, a part of it is reflected back to the electronic module. The efficiency of the reflected signal depends on the dielectric constant difference of the mediums. The reflected pulse is detected as an electrical voltage signal and is then processed by the electronics. Level distance is directly proportional to the flight time of the pulse. The measured level data is converted to 4-20mA current and HART® signals and is displayed on the LCD display. The TDR-2000 is unaffected by the other properties of the medium as well as that of the space above it. |  |