A triple beam balance is a device that measures the mass of an object by comparing it with a system of three counterweights. The advantage of using this system is it allows you to measure the weight of an object extremely precisely. You can measure the mass of an object by learning to move the sliders and interpret the scales on each of the three beams.
Move each slider on the three beams to the far left so the pointer is straight and aligned with the central mark on the balance.
Place the object you want to weigh on the balance's pan and allow a few seconds for the balance to settle. The pointer will now be above the central mark.
Move the slider on the 100 gram beam to the first mark on the right, which is the 100 gram mark. If the pointer still is above the central mark, continue to move the slider to the right. Once the pointer drops below the central mark, move the slider back to the previous mark to the left. If the pointer drops below the central mark at 100 grams, move the slider back to zero.
Move the slider on the 10 gram beam to the 10 gram mark. Perform the same adjustments you did in the previous step until you find the appropriate slot for the 10 gram slider.
Repeat the same process with the 1 gram slider.
Add the values from each slider. For instance, if the 100 gram slider is on 200, the 10 gram slider is on 40 and the 1 gram slider is on 1.5, you would add 200 plus 40 plus 1.5 to get a total of 241.5 grams as the mass of your object in the tray.