Over time, every scale becomes inaccurate due to constant use and will need to be recalibrated. A scale showing an inaccurate weight can be very frustrating, and will continue to produce false readings until it is corrected. General purpose scales contain a knob or another type of tool for calibration, which makes it easier to achieve the required calibration accuracy. To calibrate weighing scales, you will need a scale and two objects which you know the weight for. These two objects should contain two very different weights. An example would be an object that weights six pounds, and another object weighing two pounds and seven ounces.

The first thing you must do is place one of the objects onto the scale. Take note of the actual weight of the object, and the weight displayed for the object by the scale. Calculate the difference between the weight displayed on the scale and the actual weight in order to determine exactly how much of a difference the scale is displaying from the actual weight.

Now it is time to begin the calibration process. Leaving the object on the scale, turn the calibration knob to calibrate the scale until the weight displayed is the actual weight of the item. When you turn the calibration knob, be sure to do so in a gentle manner to ensure that you do not further distort the calibration of the scale. The weight may be off by several pounds, or only a couple of ounces; which shows how important it truly is to adjust the scale very carefully. Adjusting the scale in a rough manner may result in damaging the weighing scale or even your hands.

Remove the object from the scale. The scale should read “Zero” when the object is removed. Place the object back on the scale. Repeat this step two to three times in order to determine if the scale is accurately calibrated and continues to display the actual weight of the object. Remove the first object and add the second one. If the weight is displayed correctly on the scale, then you know you have accurately recalibrated the scale.

You will want to perform this calibration process periodically in order to continually achieve accurate readings from the scale.
photo credit: dno1967b