Neutron ray measurement of asphalt content in asphalt mix - incorporates detector for equating loss of neutron energy due to hydrogen atoms in asphalt with total asphalt content

摘要

A device for measuring the asphalt content of an asphalt cpd. is incorporated in an installation for mixing the asphalt and is used to automatically maintain the asphalt content at a standard value. The measuring equipment comprises a neutron gun which transmits neutron rays which react with hydrogen atmos in the asphalt component of the mix in such a way that the energy of the neutron stream is reduced. A sensor registering the neutron energy is connected to an element which responds to the sensor output and controls the asphalt content. The energy of the neutron gun is pref. is approx. 1 MeV whilst that of the sensor is approx. 1 eV. The source is pref. a 24/Am+Be whilst the detector is BF3 or He3. The measuring and control device can be incorporated in a recirculating mixing system to automatically produce a mixt. with the correct asphalt content. It can also be used to recycle old asphalt to produce new asphalt with a predetermined asphalt content.