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Introduction To Lab Equipment

Introduction To Lab Equipment. Lab Equipment. Triple Beam Balance Graduated Cylinder Ruler (metric) Ruler (standard) Meter Stick Spring Scale Thermometer. Triple Beam Balance (Overview). Used to measure mass Unit of measure: gram (g). Pan. Balance/Zero Mark. Zero Adjustment

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Introduction To Lab Equipment

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  1. Introduction To Lab Equipment

  2. Lab Equipment Triple Beam Balance Graduated Cylinder Ruler (metric) Ruler (standard) Meter Stick Spring Scale Thermometer

  3. Triple Beam Balance(Overview) • Used to measure mass • Unit of measure: gram (g) Pan Balance/Zero Mark Zero Adjustment Knob (below pan) 3 Riders/Movable Masses (top-down = tens, hundreds, ones)

  4. Triple Beam Balance(How to Use) • Place the balance on a flat, level surface. • Move all riders to the left (zero). • Determine if the pointer is at the zero mark. If at the zero mark move to step five – if not at the zero mark, complete step four. This should be done at eye level. • Turn the zero adjustment knob counter-clockwise (up) to have the pointer move upward or turn the knob clockwise (down) to have the pointer move downward – this knob should be adjusted until the pointer is at the zero mark. • Place the object on the pan. • Move the largest rider (hundreds) to the right until the pointer falls below zero – you should feel the rider click as it moves along. The rider must be “clicked” into place in order to get accurate measurements. You should move the rider one notch back after the pointer falls below zero. • Repeat step six with the tens rider. • Move the ones rider to the right until the pointer is at the zero mark. • Determine the object’s mass, in grams, by totaling the numerical values highlighted by the hundreds, tens, and ones riders.

  5. Triple Beam Balance (Example) • What is the mass of the object being measured by the triple beam balance if the sliders/movable masses have the shown positions? 30 g (tens) 0 g (hundreds) 2 g (ones) + 32 g

  6. Graduated Cylinder(Overview) • Used to measure volume • Unit of measure: milliliter (mL) • Come in a variety of sizes • Value of graduated markings, or lines, change as the size of the graduate changes • Using the smallest possible graduated cylinder typically results in more accurate measurements Each of these lines represent graduated markings

  7. Graduated Cylinder(Graduated Markings) • To accurately determine volume when using a graduated cylinder, it is important to figure out the value of each graduated marking • This can be done by identifying the difference between two consecutive, printed numbers on the graduate and then dividing that by the number of lines between them. What is the value of each line? In this case, the difference between 80 and 70 mL is 10 mL. If I then count the number of lines (not including the first one) between those two numbers I get 10 lines. If I divide the 10 mL by the 10 lines you should get 1 mL per line.

  8. Graduated Cylinder(Meniscus) • The meniscus is the curved line that the liquid makes inside of the graduated cylinder as a result of the adhesion and cohesion properties of the liquid If each graduated marking has a value of 1 mL, what would be the volume of the liquid if you read the graduated cylinder from the bottom of the meniscus? Meniscus For this example, the volume of the liquid would be 62 mL since the bottom of the meniscus falls on the 62 mL mark.

  9. Graduated Cylinder (How to Use - Liquids) • Select the smallest possible graduated cylinder that can accommodate the amount of liquid you will be measuring. • Determine the value of each graduated marking, or line, found on the graduated cylinder – knowing this will help you determine the volume. • Place the graduated cylinder on a flat, level surface. • Carefully pour the liquid into the graduated cylinder without spilling any. • Measure the level of the water by looking at the bottom of the meniscus. This should be done at eye level.

  10. Graduated Cylinder (Example) • What is the volume of the liquid in the graduated cylinder? Meniscus Since each graduated marking is equivalent to 1 mL, the volume of the liquid in the graduated cylinder is 48 mL

  11. Graduated Cylinder (Water Displacement - Overview) • Water displacement is a process by which a graduated cylinder is used to determine the volume of a solid object, particularly one that is irregularly shaped. • The volume is calculated by observing the amount of water displaced by the submerged object. Initial Volume (water) Final Volume (water + rock) Meniscus Notice how the water level rose after the object was placed in. This rise of the water helps you figure out the object’s volume.

  12. Graduated Cylinder (How to Use – Water Displacement) • Select the smallest possible graduated cylinder that can accommodate the object you will be measuring. • Determine the value of each graduated marking, or line, found on the graduated cylinder – knowing this will help you determine the volume. • Fill the graduated cylinder with enough water to adequately submerge the irregularly shaped object you will be measuring. However, do not fill it so much that water will rise past the graduated cylinder’s graduations when placing the irregularly shaped object in. • Place the graduated cylinder on a flat, level surface. • Measure the level of the water by looking at the bottom of the meniscus and record the volume (initial). This should be done at eye level. • Carefully place the irregularly shaped object into the graduated cylinder. This can be done by angling the graduated cylinder and allowing the object to gently slide down the side into the water. • Measure the new level of the water by looking at the bottom of the meniscus and record the volume (final). This should be done at eye level. • Calculate the volume of the irregularly shaped object by subtracting the initial volume (measured in step five) from the final volume (measured in step seven).

  13. Graduated Cylinder (Water Displacement - Example) • What is the volume of the rock in the graduated cylinder? Initial Volume (water) Final Volume (water + rock) Meniscus 28 mL 38 mL 38 mL (final volume) - 28 mL (initial volume) 10 mL

  14. Ruler (metric)(Overview) • Used to measure length/distance • Units of measure: centimeters (cm), millimeters (mm) • Markings • Each small (unnumbered) line is a millimeter division • Each long line followed by a number is a centimeter division • 10 millimeters in a centimeter 1 mm 1 cm Important – this is only a portion of a ruler

  15. Ruler(How to Use) • Choose an object to measure and place it on a flat surface. • Align the ruler to the side of the object with the beginning of the object at the zero mark. Be careful, some rulers have the zero mark at the starting edge and some have a zero mark slightly indented. • Locate the opposite edge of the object and read the last number on the ruler where the object ends.

  16. Ruler (metric)(Example) • What is the length (millimeters and centimeters) of the object below? 37 mm 3.7 cm What is the relationship between your two answers?

  17. Ruler (standard)(Overview) • Used to measure length/distance • Units of measure: inches (in), feet (ft) • Markings • The smallest lines show divisions of 1/16th inch • The small lines show divisions of 1/8th inch • The medium lines show divisions of ¼ inch • The long lines show divisions of ½ inch • The long lines followed by a number show divisions of 1 inch 1 1/16th 1/8th 1/4 1/2 Important – this is only a portion of a ruler

  18. Ruler (standard)(Dissection) Parts of an inch 16 Sixteenths 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 7 8 Eighths 1 2 3 4 5 6 7 8 4 Fourths 1 2 3 4 2 – Halves 1 2 Combining Each Part 1/2” 1” 1/4” 3/4” 1/8” 3/8” 5/8” 7/8” 1/16” 3/16” 5/16” 9/16” 11/16” 13/16” 15/16” 7/16”

  19. Ruler(How to Use) • Choose an object to measure and place it on a flat surface. • Align the ruler to the side of the object with the beginning of the object at the zero mark. Be careful, some rulers have the zero mark at the starting edge and some have a zero mark slightly indented. • Locate the opposite edge of the object and read the last number on the ruler where the object ends.

  20. Ruler (standard)(Example) • What is the length (inches) of the object below? Round to the nearest 1/16th of an inch. 1 7/16 inches

  21. Meter Stick(Overview) • Used to measure length/distance • Units of measure: meter (m), centimeter (cm), millimeter (mm) • Markings • Each small (unnumbered) line is a millimeter division • Each long line followed by a number is a centimeter division • 10 millimeters in a centimeter • 100 centimeters in a meter How many millimeters are in a meter? 1 mm 1 cm Important – this is only a portion of a meter stick

  22. Meter Stick(How to Use) • Choose an object to measure and place it on a flat surface. • Align the meter stick to the side of the object with the beginning of the object at the zero mark. Be careful, some meter sticks have the zero mark at the starting edge and some have a zero mark slightly indented. • Locate the opposite edge of the object and read the last number on the meter stick where the object ends.

  23. Meter Stick (Example) • What is the length (in meters, centimeters, and millimeters) of the object below? 0.246 m 24.6 cm 246 mm

  24. Tubular Spring Scale(Overview) • Used to measure weight • Units of measure: newton (N), gram (g) • Dependent on gravity • Come in a variety of measurement capabilities (100g/1 N – 10,000g/100 N) - usually indicated by different colors for tubular scales • Value of graduated markings, or lines, vary with the spring scale’s capacity • Using a spring scale with the smallest possible capacity typically results in more accurate measurements Adjustment Nut Ring Spring Pointer Graduated Markings Hook

  25. Tubular Spring Scale(How to Use) • Select a spring scale with the smallest possible capacity that can accommodate, or measure, the weight of your object. • Determine what scale you will be using (newtons or grams). • Similar to when using a graduated cylinder, determine the value of each graduated marking, or line, found on the spring scale – knowing this will help you determine the weight. • Hang the ring of the spring scale on a sturdy object such as a ring stand (with clamp) if possible. • Determine if the pointer is at the zero mark. If at the zero mark move to step seven – if not at the zero mark, complete step six. This should be done at eye level. • Zero the spring scale by turning the adjustment nut at the top clockwise to raise the pointer and counter-clockwise to lower the pointer – the nut should be adjusted until the pointer is at the zero mark. • Carefully hang the object on the hook. • Measure the object’s weight by reading where the pointer falls on the scale. This should be done at eye level.

  26. Tubular Spring Scale (Example) • What weight (in newtons) is being displayed by the spring scale? Since each graduated marking is equivalent to 0.5 N, the weight being displayed by the spring scale is 6 N.

  27. Thermometer(Overview) • Used to measure temperature • Units of measure: Celsius (0C), Fahrenheit (0F), Kelvin (K) • Relies on the expansion and contraction property of fluids – this is why the fluid (alcohol) rises as the temperature goes up and falls as the temperature goes down • Celsius and Fahrenheit scales meet at – 40 degrees • Relationships between scales: • 0C = 5/9 (0F – 32) • 0F = 9/5 0C + 32 • K = 0C +273

  28. Thermometer(How to Use) • Determine what scale you will be using (Fahrenheit or Celsius). • Similar to when using a graduated cylinder or spring scale, determine the value of each graduated marking, or line, found on the thermometer – knowing this will help you determine the temperature. • Set up a ring stand with clamp on a flat surface. • Carefully tighten the thermometer into the clamp. • Place the object/substance to be measured on the base of the ring stand. • Lower the thermometer into the object/substance. Be sure to not allow the bulb of the thermometer to sit on or touch the container holding the object/substance. • Measure the temperature of the object/substance by reading where the top of the red liquid (alcohol) aligns with the appropriate scale. This should be done at eye level.

  29. Thermometer (Example) • What is the temperature (in degrees Fahrenheit and Celsius) being displayed by the thermometer below? 74 0F 23 0C 0F 0C

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