Pig including an X-ray fluorescence sensor

A pig for use in a pipeline for determining the material of the pipeline in the context of an inline inspection, the pig comprising:

• a position determination unit;
• at least one braking arrangement for immobilizing the pig at a certain position in the pipeline;
• an X-ray fluorescence sensor and/or an atomic emission spectroscopy arrangement (AES arrangement);
• and
• a bypass system with a bypass valve through which a fluid flowing in the pipeline is led past the pig and/or through the pig,
• wherein the bypass valve is pivotable about a pivot axis, wherein the bypass valve is asymmetrical about the pivot axis and is arranged on the pig so that the part of the bypass valve with a larger surface area can be acted upon by a fluid flowing in the pipeline with a force which moves the bypass valve in the direction of the closed position.