Protective tube device for protecting a temperature sensor against contact with a fluid

A protective tube device for protecting a temperature sensor against contact with a fluid, the device comprising:

• a distal end including the temperature sensor and including an outer wall configured to contact the fluid;
• and
• a proximal end, connected to the temperature sensor by one or more electric lines, suitable for arrangement outside the fluid,
• wherein, on the outer wall of the distal end, the outer wall includes an elastic membrane that closes off a pressure transmission fluid reservoir in a fluid-impermeable manner,
• wherein the pressure transmission fluid reservoir is defined by the elastic membrane and the outer wall,
• wherein the pressure transmission fluid reservoir is connected fluidically by a fluid channel to a pressure sensor arranged in the proximal end,
• wherein the fluid channel runs within the protective tube device,
• wherein the outer wall of the distal end includes a depression in a region closed off by the elastic membrane, thereby increasing a volume of the pressure transmission fluid reservoir, and
• wherein an edge of the depression is of oval shape.