The piece of equipment used to measure mass is called a scale or balance.

Here's a breakdown:

* Scale: This is a general term for any device that measures mass. They come in many varieties, from simple kitchen scales to highly precise laboratory balances.

* Balance: This refers to a specific type of scale that uses a lever and weights to determine mass.

While "scale" is the more commonly used term, it's good to know that "balance" can also be used.