Carbon black is a finely-dispersed carbon product used in manufacturing of rubbers and other plastic materials. Carbon black (soot) is a loose product.
A size of carbon-black particles is very small; airborne particles during handling operation penetrate all accessible holes, and potentially bring level transmitters having movable parts out of service or clog unprotected measurement elements of noncontact level transmitters.
During storage, carbon black creates loose, open mass, which considerably absorbs electromagnetic radiation rather than reflects it. The air/product interface is fuzzy, and the loose nature of carbon black makes the product surface uneven, which additionally dissipates the reflected electromagnetic signal. Therefore, stable and accurate level measurement can hardly be expected with either pulse noncontact radar level transmitters or radar level transmitters with a wide measuring beam and an operating frequency of 10GHz or lower.
The ULM-11 level transmitter is most efficient in carbon-black (soot) level measurement. The ULM-11 level transmitter operates at a frequency of 94GHz and has the highest sensitivity among currently produced radar level transmitters.
When there are no mandatory explosion-safety requirements, the carbon black level can be measured using the ULM-31A1.
ULM level transmitters are successfully used for level measurement of both granular and nongranular carbon black. Level measurement is continuous.