Probe for checking the presence of paramagnetic particles in a tank

A probe for use with a tank having a wall pierced by an orifice and wherein the tank is configured to contain a fluid containing paramagnetic particles, said probe comprising:

• a magnet,
• a displacement system configured to be arranged at the orifice and to displace the magnet from a capturing position in which the magnet is bathed in the fluid to a checking position in which the magnet is outside of the tank, and
• sealing means configured to provide a seal-tightness of the orifice in a transition from the capturing position to the checking position and from the checking position to the capturing position,
• wherein the sealing means comprise:
• a first blind cylinder with an open end configured to be fixedly mounted in the orifice and a blind end configured to dip into the fluid, wherein a part of a cylindrical wall of the first blind cylinder which is configured to dip into the fluid is pierced by first passages separated by solid parts of the cylindrical wall of the first blind cylinder, and
• a second blind cylinder having an open end disposed at the open end of the first blind cylinder and a blind end disposed against the blind end of the first blind cylinder, wherein the second blind cylinder is rotatably mounted inside the first blind cylinder, wherein a cylindrical wall of the second blind cylinder is pierced by second passages separated by solid parts of the cylindrical wall of the second blind cylinder,
• wherein the first passages and the second passages are disposed in such a way that, in the capturing position, a second passage is facing a first passage and in such a way that, in the checking position, each second passage is located facing a solid part of the cylindrical wall of the first blind cylinder and each first passage is located facing a solid part of the cylindrical wall of the second blind cylinder, and
• wherein the displacement system comprises a plug which is screwed to the second blind cylinder at the open end and wherein the magnet is fixed to a face of the plug oriented towards an inside of the second blind cylinder.