If you are going to use the device on your finger, clean your nails and make sure any polish or varnish, as well as false nails, are removed Turn the oximeter on and ensure that light shining between the clips If using on your nail, clip the device onto your finger If using on your ear, then clip to your earlobe Make sure the light shines through the nail bed or earlobe The reading will be displayed in a few seconds One the monitor has stabilised then take the reading … [Read more...] about The £20 gadget that could spot whether you’re at risk of severe Covid