Analytical Balance

ANALYTICAL BALANCE

Introduction

Analytical balances are accurate and precise instruments used to measure masses. They require a draft-free location on a solid bench that is free of vibrations. Some modern balances have built-in calibration masses to maintain accuracy. Older balances should be calibrated periodically with a standard mass.

Here are a few tips to follow to insure proper care whenever you are using an electronic balance of any kind:

Do not bump or place objects on the bench after zeroing the balance.

Mass powders on paper or dishes. Handle objects with tongs, tweezers, gloves, or paper to prevent fingerprints.

Let hot objects cool before massing.

Mass hygroscopic materials rapidly since they will absorb water during massing.

When making repetitive massings always use the same procedure.

DO NOT go off and leave spilled chemicals on or around the balance! Report any spill to the instructor so that she may clean it up in a proper manner, re-calibrating if necessary.

Picture of the Mettler AJ100 analytical balance:
Mettler AJ100 Balance
Operating Instructions for the Mettler AJ100 Balance:

Before turning on, be sure that the doors are closed and the pan is not touching the draft ring.
Turn on by pushing down on the gray bar and letting up quickly.

Push again if the digital readout does not show 0.0000 g.

Place object in the center of the pan and close door(s).

Allow display to stablize; (g) will appear after the nummerical display.

Read (record) result, remove object from pan, leave doors closed and re-zero if necessary.

Picture of the Fisher analytical balance:

Operating Instructions for the Fisher Balance:

This balance is always left turned on, so just be sure that the readout is 0.000 and (g) is showing as the unit.

Push on the large, red square labeled "Tare", if re-zeroing is necessary. Repeat until only zeros are on the display.

Place object in the center of the pan.

Allow display to stablize; (g) will appear in the unit area of the display.

Read (record) the mass, remove object from pan, and re-zero if necessary.

Send questions, comments or suggestions to
Gwen Sibert, at the
Roanoke Valley Governor's School
gsibert@rvgs.k12.va.us

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