Measurement Tools

Length

Most rulers have English units on one side (in.) and metric units on the other side (cm, mm). The top side of this ruler shows inches. Notice that 16 lines make up each inch. If an object measure 10 lines past 1 inch, the object is 1 10/16 inches long. You can reduce this measurement to 1 5/8 inches.	Now the top side of this ruler is showing metric units. Each large line with a number gives the number of centimeters, while every little line is a millimeter. You can count and see that there are 10 mm in a cm. If an object measures 9 lines in (1 line short of the 1), the object is 9 mm long. An object that measures two lines past the 1 is 1.2 cm long (1 cm and 2 mm).

Mass

There are many ways to determine the mass of an object. We will use a triple beam balance. It is similar to the scale they use in the doctor's office. In order to get an accurate reading, move the weights on the three beams all the way over to zero. Place your object on the tray on the balance. Start with the largest weight, the one in the back. Move it over one spot to the right and make sure that it locks in place. If the pointer on the side opposite the tray remains above the line, you can move the weight over one more place. Once the pointer drops below the line, you need to move the weight back to the left one place. Then repeat the procedure with the weight in the middle and then the weight in the front. You'll have to continue to adjust the weight in the front until the pointer points exactly to the line. Finally, add together the readings for the three weights. If the back weight read 100 g, the middle one 10 grams, and the front one 4.2 grams, the mass of the object is 114.2 grams. Volume Flask Beaker Graduated Cylinder Flasks, beakers, and graduated cylinders are used to measure liquid volumes. The units used on these tools are generally milliliters. Flasks and beakers are good for mixing chemicals. A flask is preferred over a beaker if you are going to be swirling a solution. A graduated cylinder will give the most accurate readings. Each milliliter is marked with ten lines. If the liquid measures two lines past the one mL line, the volume of the liquid is 1.2 mL. The dip in the fluid is referred to as a meniscus. Measure from the bottom of the dip to get an accurate reading. Temperature Most thermometers have degrees Fahrenheit on one side and degrees Celsius on the other side. You need to pay attention to how the numbers are divided up on a thermometer. Each line may stand for a tenth of a degree, one degree, two degrees, etc. depending on the thermometer. Go on to the metric system page. Return to the instructions page.