How is Zero & Tare Different on a Scale?

On most scales or laboratory balances you will often see a “Zero” button and you will probably see a “Tare” button as well. What do these two buttons do?  Are they the same?

If you’ve pressed these buttons before, they might seem like they do the same thing.  Actually, they are similar, but they actually do different things.

zero vs tare

ZERO BUTTON ON A SCALE OR LAB BALANCE

The “Zero” button should be pressed when the scale is a graduation or two away from zero and you would like it to be perfectly on 0.00 before you start weighing. For example, if you have a floor scale and it is flashing between 0 and 1 lb.  If you press the “Zero” key, that will hopefully zero the scale off and it will be ready for weighing.

Technically, the zero point is actually set during the scale calibration along with span calibration. Why would you have to zero the scale?  Perhaps there is some buildup on the scale platform that has accumulated since the scale was last calibrated or perhaps the scale needs to be re-calibrated… 

Basically, the “Zero” button should only be pressed when no load is on the scale. On legal for trade scales, there is a limit to how much weight you can “zero off” the scale.

TARE BUTTON ON A SCALE OR LAB BALANCE

What does tare mean?  The “Tare” button is pressed when you have placed something on the scale (like a box, container, or empty truck) and you need to disregard the weight of that item. After adding the truck or container to the scale, pressing the “Tare” key will set the display to display 0.00 and then whatever you’re looking to weigh can then be added to the scale in the “Net” mode.

For example, let’s say you are using a parts counting scale and you often use a plastic container when you are counting out bolts. You place the empty plastic container on the scale, press “Tare” and then count parts. The only weight you will see on the scale is the weight of the bolts (and the number of bolts, since you are counting them).

Then when you’re finished, you can remove the plastic container from the scale. When you do this, the weight of the plastic container will still be displayed since you “tared” that off earlier. You then press the “Tare” key to remove that container weight from the scale and the display will once again be showing 0.00 and ready to weigh.

It’s a good idea to have your scales calibrated on a regular basis with certified test weights by state certified scale technicians. This will make sure the zero of each scale or lab balance is set correctly and the span from zero to the max capacity is correct. Contact the service department by calling (919) 776-7737 to get your scales checked.