I think there is a little gasket , that sits under the contact plate . I think they are very similar to the Vamo , in this respect . That being said , you need to replace it with a size 60 o-ring ( lowes or home depot ) in the plumbing dept . I had to cut mine in half , to get in in , before I
threw my Vamo into the trash . Worked at it for an hour , with no success . After I cut it in half , took less than 2 minutes . Gently raise the contact plate , with a dental pick , or very small screwdriver . Move it to one side of the opening , and insert one half of the o-ring , down , and under the plate . Then lift the contact plate up and over to the other side (contact plate will be covering the piece , you just put in . Then put in the other half . All done . Now the readings should rturn to normal . I have done this on both mine , and my wifes Vamo's , and have had no problems , with either , since . good luck .