The KOBOLD NGM guided wave radar level transmitter employs time domain reflectometry (TDR) technology, which is also known as “guided microwave” or “guided wave radar”. Low-energy and high-frequency electromagnetic impulses, generated by the sensor’s circuitry, are propagated along the probe, which is then immersed in the liquid or solid to be measured. When these impulses hit the media’s surface, part of the impulse energy is reflected back up the probe to the circuitry. The level is then calculated from the time difference between the impulses sent and the impulses reflected. The NGM can transmit the level as a 4-20 mA analog output or it can convert the values into a freely programmable switching output signal.