I have an idea in my head, I don't want to go into much detail right now, however I was wondering if anyone might be able to help me with some examples.

There are many weights and measures puzzles out there...

The measuring jugs, where you have to measure an amount of water but where all the jugs are either larger or smaller and while you know the volume of each jug, they are not marked so you cannot judge their partial volume.

The hour glasses where you know the length of time the hour glasses take to empty, but you need to measure a length of time different to the hour glasses.

The weights, where you have multiple items that are supposed to weigh the same and 1 (or more) weigh more or less, and you have to sort them without anything else but a set of balances and the items themselves.

The weights II, where you have several numbered weights, and have to balance the scales by placing the different numbered weights at different points along the balance arm (force=weight×distance).

And I don't want any of those!

I am looking for examples of a balance puzzles where you have to find either the exact weight of 1 item, or weigh out a certain amount of 1 item using a standard set of balances (the fulcrum and receptacles do not move) and a limited number of graduated weights.

And I can't find anything!

Does anyone know of such puzzles?

Can you point me in their direction if so.

Thanks.

Well after that long post, I have managed to find one example...

In a game called "Hellraid: The Escape" you have to make 2 potions by mixing and heating crystals.

Both times you are given the recipe, a balance and 3 weights (2, 3 & 5).

The first recipe calls for 14 units of blue gem, 12 units of orange gem and 6 units of green gem.
The second recipe calls for 7 units of blue, 8 of orange and 18 of green.

Using the balance, I found the following...

Placing a blue gem on one side of the scales and weights 2 & 5 on the other balanced. Thus a blue gem weighs 7 units.

Placing an orange gem + weight 3 on one side of the scales and weights 2 & 5 on the other balanced. Thus an orange gem weighs 4 units. (7-3).

Placing a green gem + weight 2 on one side of the scales and weights 3 & 5 on the other balanced. Thus a green gem weighs 6 units (8-2).

So recipe 1 needs 2 blue, 3 orange and 1 green gem, while recipe 2 needs 1 blue, 2 orange and 3 gems.

Does anyone know of any more puzzles like this?

Well... Why don't you start from there?
70% of what you wanted are already embedded in the example given by you, after all