How to Test Accuracy on Your Digital Weight Scale
A digital weight scale takes the guesswork out of weighing anything from a pack of paper clips to watermelon to your own body weight. If you are on a diet or mixing chemicals, then the accuracy of a digital weight scale is important. If the weight is off by as much as a gram, your experiment or strictly controlled diet could be ruined. Periodically, you should check the accuracy of your digital weight scale, and this article will show you how to calibrate it correctly.
Step 1 - Weigh a Weight
It is important to use a weight that is accurate or else the digital scale will never be correct. This means, do not simply test with a box of product that says it weighs 1 pound because they often weigh either more or less by a small fraction. The only acceptable weight is one that is plastic or metal. They can be found at many hardware stores. Since you know that the weight is exactly one pound, you can use it to test the digital weight scale. Turn the scale on, and allow it to warm up for about a minute prior to adding the weight. Once the scale is warmed up, place the weight on the center of the scale. Give it several seconds to weigh and check out the final weight. If the scale registers one pound then it is accurate, but if it is off, you will need to calibrate the scale.
Step 2 - Ready the Scale for Calibration
Remove the weight from the scale and turn off the power. Let the digital weight scale cool down for a few minutes. This allows the scale to reset. After the cool-down period, turn the scale back on. You will need to find the button used to calibrate the scale. This can appear in a variety of ways including:
If none of these appear on your scale, it may be located on the back. Turn the scale over and look for a very small hole. If you insert a paperclip into the hole, it will allow you to enter the function mode of the digital weight scale. Press the proper button and hold it down. After a short period of time, the screen on the scale will change. Most scales will begin to show one of three things:
The scale will be in calibration mode when the screen changes to show "CAL," which is then followed by a number. Some digital scales may just show a number without first showing the "CAL" on the screen.
Step 3 - Calibrate the Digital Weight Scale
The scale is ready for you to place the weight onto it. Allow the weight to remain in place for at least 5 seconds. Once the scale has settled on the weight of the weight, hold down the calibration button. The display will read "0," "END" or "CAL". Turn the scale off when this happens. After 30 seconds, turn the scale back on. It will now be calibrated.