Device with disposable element

An element 300 comprising a body 310 comprising an upper section 310a and a lower section 310b joined by a flexible arm 310c, the upper section comprises an opening 313 and the lower section is attached on its underside to a spring 320; and a printed film 330 comprising tabbed 330a and non-tabbed 330b areas and first and second faces, wherein the tabbed area comprises a sensor comprising two electrodes 350a, 350b (Figure 13B) on its first face, and the tabbed area is inserted between the upper and lower sections so that the sensor is aligned with the opening. The non-tabbed area may comprise contact pads (Figure 13B). The non-tabbed area may contact the spring. The two electrodes may be concentric A detachable element for use with a reusable component is also discussed (Figure 1B). A connector (Figure 2 is also discussed). A further detachable element (Figure 7B) is further discussed.