| 摘要 |
<p>Apparatus (10) and method for measuring the concentration of particles in a gas using an electrode (20) disposed within but electrically insulated from an electrically-conductive conduit member (12), a current measuring device (3) and means (32, 38) for maintaining the conduit member and the electrode at substantially the same potential. Flow of gas containing charged particles along the conduit induces a current passing from the electrode through the current measuring device. If the concentration of particles in the gas becomes excessive, the current measuring device activates a warning device (35) or takes other action to prevent damage to any gas-consuming device attached to the apparatus. The apparatus might include an optional ionizer (40) up-stream of the electrode to charge the particles in the gas. </p> |
