Learning Outcome 3
Maintain measuring instruments
PERFORMANCE STANDARDS
Measuring instruments are not dropped to avoid damage.
Measuring instruments are cleaned before and after using
Proper storage of instruments is undertaken according to the manufacturer’s specifications and standard operating procedure.
What Do You Already Know?
Let us determine how much you already know about maintaining measuring instrument. Take this test.
What Do You Need To Know?
Read Information Sheet 3.1 very well then find out how much you can remember and how much you learned by doing Self-check.
Information Sheet 3.1
Measuring instruments in electronics are confined only to analog testers and sometimes digital millimeter. Either way the maintenance of these instruments is a priority in all electronics laboratory rooms.
Electronic Measuring Instruments
Aside from hand tools, measuring instruments are also needed for more accurate and quality output. In this connection, three of the most used instruments are presented here for you to be familiar with their uses and the proper way of maintaining them.
Volt-Ohm-Milliammeter. It is equipment that combines three functions: as a voltmeter that measures both ac and dc voltages; an ohmmeter that measures resistance; and milliammeter that measures small amount of dc current. As safety precautions in the maintenance of this instrument, the following should be observed:
Proper care and maintenance of the multimeter
Read manual of instructions on how to operate the multi-tester.
In reading the amount of voltage, always start with the highest range to avoid reading voltage higher than the tester setting.
Be sure that the tester is set to the correct range setting: resistance range when measuring the ohm, voltage range when measuring voltage and ammeter range when measuring the value of electric current.
Always check the condition of its battery. Worn out batteries will damage the internal setting of the tester.
When the tester is not in used or will be stored, set the selector switch to 1000V or to OFF position.
Never drop the tester.
Always rest the function switch at 250V AC, if an OFF position is not available in the instrument.
For current and voltage measurements, always set the function switch in the correct setting which is a little higher than the expected current or voltage present in the circuit.
Place the instrument in a cool dry place, away from any magnetic devices, and free from vibrations.
Oscilloscope. An oscilloscope (commonly abbreviated CRO, for cathode-ray oscilloscope, or scope) is a piece of electronic test equipment that allows signal voltages to be viewed, usually as a two-dimensional graph of one or more electrical potential differences (vertical axis) plotted as a function of time or of some other voltage (horizontal axis).
Signal generator. A signal generator is a device which produces simple wave forms.
Such devices contain an electronic oscillator, a circuit that is capable of creating a repetitive waveform. These are typically used in simple electronics repair and design where they are used to stimulate a circuit under test. These are typically used in simple electronics repair and design where they are used to stimulate a circuit under test. Oscilloscope and signal generator should be given regular checkup for at least once a week by connecting them in the power line. This will help prevent their components from having moisture that might cause trouble in their circuits.
In any activity involving skills, it is a standard procedure that you must always use the right tool or equipment properly that would fit in a particular task. In spite of this reminder or caution, some students abuse the use of tools and still practice the following common faults that must NOT be done.
