TDR Radar Level meter

Product description

RD685X series transmitters are the advanced radar level measuring instruments. The Max. measuring range is up to 30m. They can be used for level measurement for storage tanks, center buffer tanks or process containers. The output analog signal is 4~20mA.

Working principle

• The electronic units generate microwave pulses which are emitted and received by the antenna systems.
• The radar wave travels at the velocity of light, the flying time will be converted into level signals via the electronic components.
• A special time extending method can make sure the stable and accurate measurement within extreme short time.
• Even under some complicated working conditions with false echoes, the level signals can also be recognized and collected with the latest microprocessor technology and the debugging software.

Input / Output

• Input — The antenna receives the reflected micro pulses and then transmits them to the electronic circuit. The microprocessor will process the signals and recognize the reflected echo from the medium surface among them. The correct reflected echoes can only be recognized by the intelligent software, the precision can reach “mm” level.
• The distance D from the medium surface is proportional to the flying time T : D = C × T / 2 (C is velocity of light)
• Due to the distance E (from the instrument flange to the bottom of the tank, i.e. the height of the empty tank) is known, then the level L is : L = E − D
• Output — By setting the empty tank height E as zero point, the full tank height F as full range point and other practical parameters, which will make the transmitter adapt to the measuring environment automatically, corresponding to output 4-20mA.