Table of Contents
What precautions must be observed when measuring current?
AMMETER SAFETY PRECAUTIONS Always start with the highest range of an ammeter. Turn OFF and discharge the circuit completely before you connect or disconnect the ammeter. In dc ammeters, observe the proper circuit polarity to prevent the meter from being damaged. Never use a dc ammeter to measure ac.
What are the three general precautions to take when measuring resistance?
Precautions in Handling and Using a Meter
- Do not drop any meter.
- Do not overload any meter.
- Do not tamper with precision instruments.
- Before you connect a meter to a circuit, ensure that the range switch is set to an appropriate position.
- Carefully check circuit connections before applying power to meters.
What is used to measure the inductance of inductor?
Inductance is usually measured in units called millihenrys or microhenrys. It is commonly measured by using a frequency generator and an oscilloscope or an LCM multimeter. It can also be calculated through a voltage-current slope measuring the change in the electrical current passing through the coil.
What precaution must be taken before removing an ammeter from a current transformer?
Hence, before removing ammeter from the circuit, the secondary winding of the current transformer must always be short-circuited by a wire of very low resistance.
What are the main precaution before measuring AC voltage?
Be mindful of the voltage you are measuring. When measuring AC voltage, for instance, do not allow the probe tips to touch one another when they are still connected to their respective point on the electrical circuit. This is to avoid shorting the circuit which can create a spark or ball of flame that can harm you.
What instrument measures inductance?
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An LCR meter is a type of electronic test equipment used to measure the inductance (L), capacitance (C), and resistance (R) of an electronic component. In the simpler versions of this instrument the impedance was measured internally and converted for display to the corresponding capacitance or inductance value.
How is inductive reactance measured?
The formula for calculating the inductive reactance of a coil is: inductive reactance, or XL, is the product of 2 times p (pi), or 6.28, the frequency of the ac current, in hertz, and the inductance of the coil, in henries. XL =2p x f x L.
What does a ohmmeter measure?
ohmmeter, instrument for measuring electrical resistance, which is expressed in ohms. In the simplest ohmmeters, the resistance to be measured may be connected to the instrument in parallel or in series. Ratio meters measure the ratio of the voltage across the resistance to the current flowing through it.
What are the important precautions which should be observed in the use of electricity?
important precautions which should be observed in the use of electricity are: Use of good quality wires. Use of fuse and proper earthing. Use of appliances in dry condition only.