GENERAL TEST EQUIPMENT INFORMATION

1-12 Testing and troubleshooting are the areas of maintenance that require the greatest technical skill. Testing procedures are referred to as measurements, tests, and checks. The definitions of these terms often overlap, depending on their use and the results obtained. For example, a power measurement and a frequency check could constitute a test of the operation of the same radio transmitter. Troubleshooting is a term which we in the electronics field use daily. But what does it mean? Troubleshooting is sometimes thought to be the simple repair of a piece of equipment when it fails to function properly. This, however, is only part of the picture. In addition to repair, you, as a troubleshooter, must be able to evaluate equipment performance. You evaluate performance by comparing your knowledge of how the equipment should operate with the way it is actually performing. You must evaluate equipment both before and after repairs are accomplished. Equipment performance data, along with other general information for various electronic equipments, is available to help you in making comparisons. This information is provided in performance standards books for each piece of equipment. It illustrates what a particular waveform should look like at a given test point or what amplitude a voltage should be, and so forth. This data aids you in making intelligent comparisons of current and baseline operating characteristics for the specific equipment assigned to you for maintenance. ("Baseline" refers to the initial operating conditions of the equipment on installation or after overhaul when it is operating according to design.) Remember, maintenance refers to all actions you perform on equipment to retain it in a serviceable condition or to restore it to proper operation. This involves inspecting, testing, servicing, repairing, rebuilding, and so forth. Proper maintenance can be performed only by trained personnel who are thoroughly familiar with the equipment. This familiarity requires a thorough knowledge of the theory of operation of the equipment. A logical and systematic approach to troubleshooting is of the utmost importance in your performance of electronics maintenance. Many hours have been lost because of time-consuming "hit-or- miss" (often referred to as "easter-egging") methods of troubleshooting. GENERAL TEST EQUIPMENT INFORMATION In any maintenance training program, one of your most important tasks is to learn the use of test equipment in all types of maintenance work. To be effective in maintenance work, you must become familiar not only with the common types of measuring instruments, but also with the more specialized equipment. Some examples of common types of typical measuring instruments are the ammeter, voltmeter, and ohmmeter; examples of specialized test equipment are the spectrum analyzer, dual-trace oscilloscope, and power and frequency meters. TEST EQUIPMENT SAFETY PRECAUTIONS The electrical measuring instruments included in test equipment are delicately constructed and require certain handling precautions to prevent damage and to ensure accurate readings. In addition, to prevent injury to personnel, you must observe precautions while using test equipment. You can find a list of applicable instructions in appendix II of this module. Instrument Precautions To prevent damage to electrical measuring instruments, you should observe the precautions relating to three hazards: mechanical shock, exposure to magnetic fields, and excessive current flow.