How to Tare a Balance Scale

To "tare" or "zero" a balance, you ensure getting an accurate measurement of weight on a balance/scale. There are several ways to do this that are important for a classroom where balances are commonly used. This skill not only ensures accurate measurements but helps meet national science teaching standards, preparing the students for subsequent science classes.

Things You'll Need

• Scale/balance
• Cloth to wipe down scale
• Tray/filter paper

Instructions

Electronic Balance (Analytical Balance)

1. Remove all items from the scale. Make sure the scale is clean and free of debris. If you wipe down the scale, make sure that the scale is completely dry before going to the next step.

2. Place the scale on a level surface. Do not move it until all measurements are complete.

3. Place any tray, filter paper, or other container that you do not want to include in the weight measurement (commonly used to keep the scale clean and hold the sample) onto the scale. If there is a chamber to block drafts (an analytical balance), close the door of the chamber.

4. Find the tare button. Look at the control panel with the buttons. There will either be a button that says "tare" or an on/off button with the word "tare" next to it.

5. Press and hold the button labeled "tare" until the digital display reads zero. If the button labeled on/off has the word "tare" next to it, press and hold the on/off button until the digital display reads zero. Release the button, and the scale readout should be zero.

Manual Balance (Three Arm Balance)

1. This step is identical to the first step (above).

2. This step is identical to the second step (above).

3. This step is identical to the third step (above).

4. Find the balance arm and pan. The pan is the place where you put the sample you are weighing. The balance arm is the part that the weights slide on next to the pan to balance it.

5. Move all balance weights on the balance arm to zero by sliding them toward the central axis of the balance. Click the weights into the notches above the zero marks on the balance arm. If the balance indicates "zero," then stop.

6. Twist the unusual-looking balance screw found under the pan of the balance. If turning the screw makes the balance go away from zero, turn the screw the other direction until the scale reads zero.

Tips & Warnings

• The reading on the scale is correct when a line or arrow at the tip of the balance arm lines up with another arrow or line on the magnetic dampener (the part that prevents the arm from swinging too wildly). The balance may require a half hour warm-up time at room temperature before calibration.

• Read and follow all directions that come with the scale. If weighing a chemical, take all precautions that are listed in the Material Safety Data Sheets (MSDS) in your school. Follow all lab safety rules established for student safety.

References

• Analytic Balance (Image)
• Instructions: Analytical Balance (Electronic Balance)
• Three Arm Balance Manual Balance (Video)

Resources

• Scale Terminology (Image)
• Analytical Balance Instructions (Video)
• Three Arm Balance Manual Balance (Video)