Fruit Penetrometer/ Hardness Tester Hard FruitsGY-3/fp503  fruit penetrometer for the scale line 0.5., will Razi the be measured fruit about 1 cm the skin.The fressure head insert the fruit the scale of pressure 10 mm,it stops . objectives of reading instruction is the fruit of hardness,for three average.This fruit penetrometer is used to measure the hardness or firmness of fruits such as apples, pears, peaches, plums, etc. The penetrometer consists of a plunger which pushes into the fruit and measures its resistance to penetration. This is an easy way to determine if your fruit is ripe enough to eat.