I would use some sort of thermometer with a lead or a small hole you in the dehydrator that will allow you to place a stick type thermometer in so you can monitor the temperature. I have one of the stainless steel units from Lem and I am not real comfortable with the thermostat settings on it. The book Great Sausage Recipes and Meat Curing by Rytek Kutas has a section on jerky and in reading the book he talks about why you should use cures.