performing measurements

• Measurement is one of the first and basic steps in the activities that we do in EIM. We need to take measurements in order to prepare the appropriate plans and prevent any subsequent error or far worse, accidents in the area.
• Module 3: Performing Measurements

  1. Use the appropriate measuring devices for specific tasks in EIM

  2. Identify the different parts of a multi-tester

  3. Interpret the readings of a multi-tester / multimeter
• Measurement


  The size, length, or amount of something, as established by measuring
• Calculation


  A mathematical determination of the size or number of something
• Graduation


  The action of dividing into degrees or other proportionate divisions on a graduation
• System of measurement


  A set of units which you can use to give the value of the thing being measured
• Unit


  A definite magnitude of a quantity, defined and adopted by convention or by law, which is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement.
• English System


  • A system of weights and measures which are commonly used worldwide, such as inch, yard, foot, mile, cup, gallon and others
• English System


  • When you want to measure the length of a pencil in an inch, you are using the English system
• Metric System


  • A system which uses millimeter, centimeter, decimeter, meter, kilometer and others
• Metric System


  • When you asked by your teachers about the distance from your home to school, you probably say it in kilometer or in meter. With this, you are using the metric system.
• Conversion of English units

  1. 1 foot (ft) = 12 inches

  2. 1 foot (ft) = 3 yards

  3. 1 yard = 36 inches
• Conversion of Metric units

  1. 1 centimeter = 10 millimeter

  2. 1 decimeter = 10 centimeter

  3. 1 meter = 10 decimeter

  4. 1 kilometer = 1000 meter
• Conversion from English to Metric units

  1. 1 inch = 2.54 centimeter

  2. 0.39 inch = 1 centimeter

  3. 1 foot = 30.48 centimeter

  4. 3.28 feet = 1 meter

  5. 1 yard = 0.91 meter

  6. 1.09 yards = 1 meter

  7. 1 mile = 1.61 kilometers

  8. 0.62 miles = 1 kilometer
• As shown above, there are 10 millimeters in 1 centimeter, 0.5 centimeter has 5 millimeters.
• As shown above, first calibration is 1/16, second calibration is 2/16 or 1/8, third calibration is 3/16 and so on.
• Multi-tester / Multimeter


  A commonly used measuring instrument in electricity wherein technician cannot perform troubleshooting without it. It's a device that performs 3 functions packed into one – voltmeter, ohmmeter, and ammeter.
• Parts of a Multi-tester / Multimeter

  • Needle Pointer - indicates the value of electrical quantity that has been measured
  • Scale Panel - usually calibrated where it serves as the basis for reading the value
  • Zero Ohm Adjuster Knob - used to adjust if ever the pointer fails to point to zero
  • Range Selector - a rotary switch of different ranges such as RX1, RX10, RX100, RX1K, and RX10K
  • Test Probes - it is the input portion of a multimeter usually coded with red and black: red means positive and black is negative
• Units measured by a multi-tester

  • Voltage in volts, represented by symbol V
  • Resistance in ohms represented by an omega symbol (Ω)
  • Current in amperes, represented by symbol A
• Procedures in interpreting the resistance reading of an ohmmeter

  1. Compute the value per calibration of the ohmmeter scale

  2. From the selector switch, select appropriate range to be used such as R X 1, R X 10, R X 100, R X 1K, and R X 10K

  3. Before connecting the test probes to the terminals of the component, make sure that the needle pointer falls to zero, if not, make some adjustments

  4. Make sure to have an accurate reading
• The ohmmeter scale is nonlinear. This means that the value per calibration may not be the same with the other calibrations. For accurate interpretation of the scale, the value per calibration should be assigned.
• Nonlinear Scale


  • 0-2
  • 2-10
  • 10-20
  • 20-50
  • 50-100
  • 100-200
  • 200-300
  • 300-500
• Voltmeter Scale


  To get the voltage value, you need to use a voltmeter. In the voltmeter you will see the following scales with corresponding calibration: 0-250 scale having 5V per calibration, 0-50 scale having 1V per calibration, 0-10 scale having 0.2V per calibration
• How to read the voltmeter scale

  1. Make sure that you are familiar with the basic parts of a multi-tester

  2. Select the range you wish to use 10V, 50V, 250V, and 1000V. Always remember, set higher/highest range than the voltage you are going to measure especially if the voltage is unknown. This is to prevent damage of your tester and electric shock

  3. Make sure that the range that you will be using is the same scale you will be reading. For example, if you set range 10 the scale is actually 0-10

  4. Read the value accurately
• The answer is 4.2V. What is the actual reading?