Liquid measures are often given in "fluid ounces" and most of us know that 8 fluid ounces = 1 cup. This does not mean that 8 fluid ounces = 8 ounces on your scale. A cup of water weighs something like 8.3 ounces, while 8 fluid ounces of honey weighs something like 15 ounces (butter has a 1:1 ratio). Even the small 3-4% difference with water can be nontrivial in baking. I would imagine that the Salter scale automatically does the conversion for water, but would be as useless as any other scale for any other liquid without a conversion table. If you find yourself weighing a lot of water this option may appeal to you -- though it's probably easier to use a measuring cup (you don't even have to wash it!). For sticky, viscous liquids like honey and molasses, it may be easiest to measure straight into the bowl on a scale, but you will have to calculate the desired weight whether or not your scale "weighs liquids."
