This device is useful for monitoring the Relative Humidity level in your home. It should be placed along side your Salin Plus device. The ideal RH level is 55%. If the RH level exceeds 70%, there is a risk that your room is too damp and the Salt Filter will absorb this moisture. A damp filter can leak water as well as reducing the effectiveness of the filter. Dust mites thrive when the RH level exceeds 65%. 

It is a very useful device to have in your home, not only to ensure that humidity will not impact the performance of your Salin Plus Salt Therapy Device but also if you are prone to allergies or have reactions to moulds or mites.