Patent ID: 8210033

Claim:
A device for detecting an accumulation amount of particulates, the device comprising: a filter trapping particulates from a gas containing the particulates; a container containing the filter; an upstream pipe, having an inside diameter, provided on the upstream side of the container to lead the gas into the container; a downstream pipe, having an inside diameter, provided on the downstream side of the container to lead the gas after the gas passed through the filter; a transmitting antenna provided within the downstream pipe to transmit an electromagnetic wave having a frequency of 30 GHz or more and 10 THz or less, wherein the frequency of the electromagnetic wave is equal to or greater than a ratio c/Di, where c is equal to the speed of light and Di is equal to the inside diameter of the upstream and downstream pipes; and a receiving antenna provided within the upstream pipe to receive the electromagnetic wave, wherein an amount of the particulates trapped in the filter is detected based on an intensity of the electromagnetic wave received by the receiving antenna.