Ambient temperature correction device for liquid expansion thermometers

In a liquid filled liquid expansion thermometer which includes a bulb for placement in the medium whose temperature is to be measured, a means for providing a temperature reading and a duct connected between the bulb and the means for providing a temperature reading, the improvement wherein said duct includes a number of temperature compensation elements along its length so as to divide the duct into a number of duct sections, each temperature compensation element being associated with a duct section, each temperature compensation element comprising a hollow shell and a solid element therein, each hollow shell defining a greater volume than the volume of the associated duct section and each solid element defining a smaller volume than the volume of the associated hollow shell, the free volume for liquid defined between each hollow shell and the solid element therein changing with temperature equally to the change in volume of the associated duct section and the volume of liquid therein.