Triple Beam balance . . . zero, adjust, and read the triple beam balance.

The triple beam balance measures mass.

Put the balance on a level surface. Slide all the masses to zero. If the two white lines don’t touch, Rotate the screw under the pan until the white lines do line up.

BELCH Once the scale is properly “zeroed”, put the object to be massed on the pan. (in this case, a delightful little hamster.) BELCH Okay. We’re ready to start moving the sliders, so let’s zoom in on them

Move the masses one at a time, starting with the biggest one. If the pan goes up, you need to move the slider backward one notch and leave it there. Once the big mass is on the correct notch, don’t ever move it again.

If putting the medium mass on 70 makes the pan go up . . . . . . slide it back to 60 and leave it there. Repeat the procedure with the medium mass.

Notice that the large and medium masses have notches on their rails.

Notice that the large and medium masses have notches on their rails. This reminds us that we should never leave the large mass or the medium mass between numbers. We must “click” the large and medium masses right onto the numbers.

Finally, slide the little mass on the front rail until the two white lines match up. Because there are no notches on the front rail, you can slide it to the exact position you want.

Usually, the little pointer on the small slider won’t point exactly to a line. For instance, the slider here is about halfway between 1.5 and 1.6. In such a case, you are allowed to estimate a hundredths digit. Since it’s exactly half-way this time, you could call this one . . . 1.55

This time, the little slider reads . . . 4.71 or so. Can you see how the pointer is just a little bit past the 4.7? Maybe you think it’s closer to 4.72 than it is to 4.71. This is where the measuring process loses some of its precision.

This time, the little slider reads about . . . 3.39. Can you see how the pointer is almost to the 3.4 but not quite?

This time, the little slider reads about . . . 8.24. This time, the pointer is about halfway between the 8.2 and the 8.3 marks, but it’s just a bit closer to the 8.2.

And now . . . some scale-reading practice.

Ok. I get it. That’s enough practice reading the numbers. 521.2 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 105.0 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 48.6 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 422.6 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 114.0 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 201.2 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 8.9 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 253.9 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 418.1 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 332.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 424.1 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 12.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 413.0 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 332.7 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 57.1 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 345.7 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 342.0 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 359.2 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 534.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 5.0 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 28.1 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 112.7 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 549.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 239.6 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 431.6 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 104.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 540.1 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 354.5 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 242.4 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 320.4 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 525.7 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 251.4 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 327.2 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 32.6 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 537.4 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 319.2 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 309.3 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 524.3 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 28.7 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

Ok. I get it. That’s enough practice reading the numbers. 115.8 grams Triple Beam Balance Demonstrator by Daniel R. Barnes, init 9/18/2006

HANDS–ON PRACTICE Each student should use the balance at your table to find the mass of one item from the materials in the box. After finding the mass, record your answer. Have your group check your answer to see if they agree. Once discussed, another student should pick a different item to find the mass and discuss.