The indoor humidity sensor can be located away from the display unit, wherever humidity monitoring is most required: in the bedroom of someone with respiratory problems, in a greenhouse or solarium, humidor or wine cellar, or in a room where valuable antiques or musical instruments are kept. Most other weather stations lack this flexibility because the indoor sensor is only located inside the keyboard/display unit.
It is same precision sensor used in out outdoor humidity unit, so it's accurate from 0% R.H. to 100% R.H. Some systems economize by using a less capable sensor indoors.
Like our outdoor humidity sensor, it will not be harmed by prolonged high humidity and can even be totally immersed in water without damage!