Abstract: A method of calibrating a heat flux sensor for measuring body temperature of an individual, and a heat flux sensor. The method includes measuring heat flux with the heat flux sensor applied to a part of the body of the individual, acquiring a reference temperature value for the heat flux sensor, the reference temperature being measured at a side of the heat flux sensor facing away from the body, and acquiring a body temperature value for the individual. Further, the method comprises determining an overall heat transfer coefficient for the sensor and the individual by using the measured heat flux, the acquired reference temperature value, and the acquired body temperature value.

Abstract: A tube for a heat exchanger provided with a helical corrugation, wherein the helical corrugation has pitch and a width, and the width being at least 20% of the pitch, such that an improved heat transfer is achieved.

Abstract: A fire warning device includes detachably connectable shell parts (1,2) which when brought together are mutually united to form a shell or casing (3) which houses a fire sensor (20), alarm emitter (21) and a power source (22). The shell (3) being provided with fire warning device suspension means (8, 9; 16, 17). The suspension means (8, 9; 16, 17) is comprised of a friction anchoring device disposed in the region of the border surface or interface (6) between the two shell parts (1,2) when the shell is closed. The friction anchoring device is disposed in a passageway that extends between two mutually opposite ends (4,5) of the closed shell and enables the shell to be closed around a rod, cable or chain that carries a light fitting, while connecting the cable, rod or chain to the friction anchoring device for suspending the fire warning device.