In measurement with radar technology, microwave impulses are emitted by an antenna onto the surface of the filled material, reflected from there and received by an electronic system. The time between transmitting and receiving the signals is proportional to the filling level in the container. Radar measurement is independent of the dust load in containers such as silos. In particularly difficult environments, a connected purging air unit ensures an “unobstructed view” for the radar antenna.
MBA Instruments GmbH supplies two radar technology products. MBA 300 is optimized for filling level measurement of bulk solids. With radar impulses, the filling height in the silo, bin or other containers, but also in stockpiles is measured continuously. Possible applications are e.g. in steel production and in the construction industry. The MBA 300 can be quickly and easily installed with a mounting bracket. The maximum measuring height is 15 m. Independent of pressure, temperature, gas, dust and sound, the product is measured in a non-contact process with high measurement accuracy. Settings can be made directly at the radar unit, a computer is not necessary.
In addition to the properties of the MBA 300, the MBA 400 (Fig.) is designed for level measurement of bulk solids and liquids even in difficult process conditions. Different possibilities for installation (G 1 ½ or flange) and an optional swivelling holder make this instrument a universal measuring device, which measures accurately with a range of 75 m. It is equipped with intelligent signal evaluation. Optional is a purging air connection for cleaning the antenna system. Different antennae are used depending on conditions. With the parabolic antenna the microwave signal is emitted by means of the transmitter-receiver and radiated in a focussed signal from the antenna surface. With the horn antenna the microwave signal is emitted by the transmitter-receiver and radiated in the direction of the antenna aperture on to the surface of the bulk solids. The curved edge of the antenna minimizes the antenna noise and improves the near-field sensitivity. With the plastic horn antenna the adjustment cone distributes the microwaves uniformly inside the antenna. The metallized interior directs the microwave signals onto the product. The lightweight and compact shape enables excellent focussing.
MBA Instruments GmbH, Quickborn (D), Tel.: +49 4106 12388-0, www.smb-group.de