This paper moisture sensor can measure the moisture content of a variety of paper types, such as kraft paper, liner board, copy paper and cardboard. The HK300 series comes in three sets with different sensor types to accommodate the type of paper to be measured and the application : the HK-300-1 set includes a grip sensor, the HK-300-2 set includes an electrically conductive rubber sensor, and the HK-300-3 set includes a constant pressure sensor.