I have purchased a scale. I had asked another trainer what strength I should expect achieve. For children I was told 10 - 16 Lbs (approximately 4.5kg - 7kg) and for adults 15 Lbs - 20 Lbs (approximately 6.5kg - 9kg). I am having difficulty getting the lip strength. I have a few adult patients and so far the highest reading is 3.5kg (approximately 7.7 Lbs). Do you have a specific lip strength range for children and adults?