Answer: the second option, analytical balance.
Explanation:
Chemical analysis may require very accurate measurements of small samples of matter, and some times that matter is in form of fine powder.
That means that air currents may interfere with the sample, either by dragging part of the sample or by depositing dust over the sample, with which the measure may result not to be as exact as desired to have an analytical result.
An analytical balance is designed to be used in labs to measure small masses with high precision. The weighing pans are inside of a compartment with glass windows which once closed avoid that the air currents to introduce dust or remove some of the sample which would lead to an erroneous measure.
