The present invention relates to a measuring device for measuring flux rate and temperature of a flowable medium, comprising an external pipe sleeve and an internal pipe provided within said external pipe sleeve, with the diameter of said internal pipe having been dimensioned such that a cavity is formed between said internal pipe and said external pipe sleeve, wherein medium is allowed to flow into said internal pipe via an aperture formed at a first end of said internal pipe, and an aperture is provided at the second end of said internal pipe via which the medium can flow out of the internal pipe and exit the measuring device via said cavity. A flux meter and a temperature meter are provided within or along this flow path formed in the measuring device.