Aprenda como usar o Multímetro Digital na Prática

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15 Aug 201812:23

Summary

TLDRIn this educational video, Bruno Everton Morais demonstrates the correct use of a multimeter, a vital tool for electrical measurements. He covers the basics of measuring voltage, current, and resistance, emphasizing safety and the importance of selecting the right scale for accurate readings. The tutorial also addresses common issues such as fragile probes and the significance of understanding the instrument's category of use. Morais provides practical examples, including checking the integrity of a conductor, ensuring viewers grasp essential electrical measurement techniques.

Takeaways

🔌 The video explains how to correctly use a multimeter, a device for measuring various electrical properties.
👨‍🏫 The presenter, Bruno Everton Morais, introduces the topic and encourages viewers to subscribe to the channel and turn on notifications for more content.
📚 The script discusses the importance of using the right multimeter for safety and accuracy in electrical measurements.
🔍 The video highlights the difference between two seemingly identical multimeters, one without any information and the other with 'KATYN 2', which indicates the category of use for the device.
🛠️ The presenter demonstrates how to measure electrical voltage, both direct current (DC) and alternating current (AC), using the multimeter.
⚠️ A caution is given about the fragility of multimeters, and the presenter shares a personal experience with a damaged probe.
🔧 The video shows how to properly connect the probes to measure voltage, emphasizing the correct placement of the red and black probes to positive and negative terminals, respectively.
🔄 When measuring AC voltage, the script explains the importance of selecting the appropriate scale on the multimeter to match the expected voltage, such as 220V for household outlets.
🔌 The presenter also covers how to measure electrical current, including the need to break the circuit open to insert the multimeter for accurate readings.
🔊 For measuring electrical resistance, the video describes the process of selecting the right scale on the multimeter and how to interpret the readings to determine the integrity of a conductor.
👍 The video concludes by encouraging viewers to subscribe for more educational content and to check out a link for an advanced training course in electrical and electronic basics.

Q & A

What is the main topic discussed in the video?
-The main topic discussed in the video is how to correctly use a multimeter for measuring electrical quantities such as voltage, current, and resistance.
Why does the presenter recommend using the yellow multimeter in the video?
-The presenter recommends using the yellow multimeter because it is the most common type that most people possess, and understanding how to use it correctly can help with using other types as well.
What is the significance of the 'Katyn 2' marking on the multimeter?
-The 'Katyn 2' marking indicates the category of the multimeter, which is important for safety and proper usage of the instrument.
What precaution does the presenter take before starting the measurement?
-The presenter takes the precaution of ensuring the multimeter is set to the correct scale and function before starting the measurement.
How does the presenter demonstrate measuring DC voltage?
-The presenter demonstrates measuring DC voltage by setting the multimeter to the appropriate voltage scale, connecting the red probe to the positive terminal and the black probe to the negative terminal, and then reading the voltage.
What is the difference between measuring AC voltage and DC voltage on a multimeter?
-The difference lies in the terminals used for measurement; for AC voltage, both probes can be inserted into either of the two slots, whereas for DC voltage, the red probe should be connected to the positive terminal and the black probe to the negative terminal.
Why is it important to choose the right scale when measuring voltage?
-Choosing the right scale is important to ensure the accuracy of the measurement and to prevent damage to the multimeter due to exceeding its maximum range.
How does the presenter explain measuring AC current?
-The presenter explains that to measure AC current, one must break the circuit, connect the multimeter in series with the circuit, and then select the appropriate current scale on the multimeter.
What is the purpose of measuring resistance with a multimeter?
-Measuring resistance with a multimeter is used to check the integrity of a conductor or to determine the value of a resistor.
What is the significance of a near-zero resistance reading?
-A near-zero resistance reading indicates that the conductor being tested is intact and has no breaks or faults.
What additional resource does the presenter mention for further learning?
-The presenter mentions a training link for further learning about electrical and electronic basics.

Outlines

00:00

🔍 Introduction to Multimeters and Safety Precautions

The video script begins with an introduction to the use of multimeters, emphasizing the importance of using the correct multimeter for accurate measurements. The host, Bruno Everton Morais, welcomes viewers to the channel and introduces the topic of the day: the correct use of multimeters. He explains the significance of the multimeter's category of use, especially for safety. The script mentions the fragility of multimeters and the importance of handling them with care to avoid damage, as exemplified by the host's own broken probe. The video then transitions into a practical demonstration of how to measure electrical voltage using a multimeter, including a brief mention of the necessary safety precautions.

05:01

🔌 Measuring AC Voltage and Understanding Multimeter Settings

This paragraph delves into the process of measuring alternating current (AC) voltage, such as the type found in household outlets. The host explains the importance of selecting the appropriate scale on the multimeter for the voltage measurement, highlighting the use of a 750V scale for common household voltages around 220V. He also discusses the significance of the multimeter's probes, using a shiny yellow and red probe for the demonstration. The host provides a step-by-step guide on how to connect the probes to measure AC voltage accurately, emphasizing the need to ensure the polarity is correct to avoid damaging the multimeter or receiving incorrect readings.

10:02

👷‍♂️ Safety and Techniques for Measuring Electrical Current

The script continues with a discussion on safely measuring electrical current, which requires a high level of caution. The host demonstrates how to measure current by opening the circuit and connecting the multimeter in series with the load. He explains the importance of selecting the correct range on the multimeter to avoid overloading the device and potentially causing damage. The host also mentions that for currents above 10 amperes, a different terminal on the multimeter should be used, and he provides a practical example of how to measure the current in a simple LED circuit, including the necessary steps to ensure accurate and safe measurements.

🛠️ Measuring Electrical Resistance and Integrity of Conductors

The final paragraph focuses on measuring electrical resistance using a multimeter, which can be useful for determining the integrity of a conductor. The host demonstrates how to measure resistance with a multimeter, explaining the process of selecting the appropriate scale and connecting the probes to the resistor. He also discusses a common use case for resistance measurement: checking whether a conductor is intact or has a break. The host shows how to use the multimeter to detect a broken conductor by measuring the resistance, which should be near zero if the conductor is undamaged. The video concludes with a reminder of the importance of understanding electrical measurements and an invitation for viewers to learn more through a linked training resource.

Mindmap

Keywords

💡Multimeter

A multimeter is a versatile electronic measuring instrument that combines several measurement functions in one unit. It is used to measure voltage, current, and resistance. In the video, the multimeter is the central tool for demonstrating how to correctly measure electrical properties such as voltage and current, highlighting its importance in electrical troubleshooting and diagnostics.

💡Voltage

Voltage, also known as electric potential difference, is the force that pushes electric charge through a conductor. It is a fundamental concept in the video, where the multimeter is used to measure the voltage in a car battery and an AC source, such as a household outlet. The script mentions measuring 'tensão elétrica' (electric voltage) to check if the battery is charged properly and to understand the voltage levels in different electrical systems.

💡Continuity

Continuity is the property of a circuit or conductor to allow an electric current to flow through it without interruption. The video discusses using the multimeter to check for continuity, which is essential for ensuring that there are no breaks or faults in a wire or circuit. This is demonstrated by measuring the resistance of a conductor and expecting a near-zero value for an intact conductor.

💡Resistance

Resistance is the measure of the opposition that a material offers to the flow of electric current. It is a key concept in the video, where the multimeter is used to measure the resistance of a resistor or to check the integrity of a conductor. The script explains that a low resistance reading indicates a good conductor, while an open circuit would show infinite resistance.

💡Ammeter

An ammeter is an instrument used to measure the current flowing through a circuit. In the video, the multimeter is set to function as an ammeter to measure the electric current in a circuit. The script mentions the importance of safety and the correct procedure for measuring current, such as opening the circuit and connecting the multimeter in series with the load.

💡Polarity

Polarity refers to the positive and negative terminals or poles of an electrical source. The video emphasizes the importance of correct polarity when measuring voltage or connecting devices to prevent damage. The script explains that the red probe of the multimeter should be connected to the positive pole and the black probe to the negative pole.

💡Safety Precautions

Safety precautions are measures taken to protect individuals from potential hazards. The video script mentions the need for safety when using a multimeter, such as ensuring the correct setting is selected to avoid damaging the device or causing injury. This includes warnings about the fragility of probes and the importance of using the correct range for measurements.

💡Range Selection

Range selection on a multimeter refers to choosing the appropriate measurement scale for the expected value of voltage, current, or resistance. The video demonstrates how to select the right range on the multimeter to ensure accurate readings. The script provides examples of selecting ranges for measuring car battery voltage and household AC voltage.

💡AC Voltage

AC Voltage, or Alternating Current Voltage, refers to the type of voltage that alternates in direction and is commonly used in household electrical systems. The video script discusses measuring AC voltage to understand the electrical supply in homes and other applications. The multimeter is set to the appropriate AC voltage range to measure this type of voltage.

💡DC Voltage

DC Voltage, or Direct Current Voltage, is the type of voltage where the electric charge flows in one direction. The video focuses on measuring DC voltage, such as from a car battery, to check if it is providing the correct power. The script explains the process of selecting the DC voltage range on the multimeter and connecting the probes to measure the battery voltage.

💡Ohm's Law

Ohm's Law is a fundamental principle in electrical engineering that states the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = I × R. Although not explicitly mentioned in the script, the concept is implied when discussing resistance and voltage measurements, which are used to calculate current in a circuit or vice versa.

Highlights

Introduction to using a multimeter correctly with a focus on the most popular models.

Explanation of the importance of understanding the category of use for measurement instruments.

Demonstration of how to measure electrical voltage using a multimeter.

Clarification on the correct placement of probes for measuring voltage in a DC circuit.

Highlighting the fragility of multimeters and the importance of handling them with care.

Instruction on how to measure AC voltage, including choosing the right scale.

The necessity of inverting the polarity when measuring voltage to avoid damage.

Guidance on measuring electrical current, emphasizing safety and circuit opening.

Details on how to measure current in a circuit with a multimeter.

Explanation of the difference in terminals used for measuring current above and below 10 amperes.

How to measure electrical resistance using a multimeter and choosing the appropriate scale.

The use of a multimeter to check the integrity of a conductor by measuring resistance.

The significance of getting a near-zero resistance reading to confirm a conductor's integrity.

Mention of a training course for further learning in electrical and electronic fields.

Invitation to subscribe to the channel for more educational content on electrical topics.