Patent ID: 7610795

Claim:
A method for adjusting a mechanical natural frequency of a pickup housing of a measurement pickup, said pickup housing at least partly comprising a ductile material, said method including the steps of: varying a static external pressure of an atmosphere surrounding the pickup housing and/or varying a static internal pressure prevailing in a substantially pressure tight-sealed lumen of the pickup housing, for generating a pressure difference between the lumen and the atmosphere surrounding the pickup housing; adjusting the pressure difference to a value that causes the ductile material of the pickup housing to expand; and causing at least a portion of the ductile material of the pickup housing to flow under the influence of the pressure difference for plastically deforming the ductile material and thereby adjusting the mechanical natural frequency of the pickup housing, wherein; said step of causing at least a portion of the ductile material of the pickup housing to flow under the influence of the pressure difference for plastically deforming the ductile material is effected without additional heating of the ductile material; and/or said step of causing at least a portion of the ductile material of the pickup housing to flow under the influence of the pressure difference for plastically deforming the ductile material is effected below a temperature of recrystallization of the ductile material.