A balance beam itself doesn't have a specific unit of measurement. It's a tool used to compare the masses of two objects.

Here's how it works:

* The balance beam: A horizontal bar that pivots in the middle.

* The pans: Two platforms attached to the ends of the beam.

* The principle: The beam balances when the weights on each pan are equal.

The units of measurement would be whatever units you are using to weigh the objects on the pans. For example:

* Grams (g)

* Kilograms (kg)

* Ounces (oz)

* Pounds (lb)

The balance beam itself doesn't tell you the weight, it just helps you determine if two objects have the same weight.