A hydration sensor or {HEAD ~ sensing element} configured to measure {TAIL ~ the hydration level} of a user is disclosed 
A hydration sensor or { HEAD ~ sensing element } configured to measure { TAIL ~ the hydration level } of a user is disclosed
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH