OHMMETER SCALE READING VIDEO PRESENTATION

Summary

In today's lesson, Mr. Ronald A. Gonzalez teaches about ammeter scale reading. He explains the non-linear scale, showing how to read resistance values from right to left, with different increments per range. He covers scales from 0 to 200 in 0.2 increments, 2 to 10 in 0.5 increments, 10 to 20 in 1 increment, 20 to 50 in 2 increments, and so on, up to 200 to 500 in 100 increments. He also discusses using the selector knob to choose the correct multiplier for high resistance values and provides a formula to calculate actual resistance. Examples are given to demonstrate how to apply the range multiplier to get the final resistance value.

Takeaways

• 📝 The video is a tutorial on how to read an ammeter scale, which is used to measure electrical current.
• 📝 The ammeter scale is non-linear, with different increments of values per line depending on the range.
• 📝 The scale ranges from 0 to 200 with varying increments: 0.2 from 0 to 2, 0.5 from 2 to 10, 1 from 10 to 20, 2 from 20 to 50, 5 from 50 to 100, 20 from 100 to 200, and 100 from 200 to 500.
• 📝 To read the resistance value, one must start from the right and move to the left, as the scale is descending.
• 📝 For high resistance values, a selector knob is used to choose the appropriate multiplier or resistance range.
• 📝 The formula to calculate the resistance value is: Resistance Value = Actual Reading × Resistance Range or Multiplier.
• 📝 The video provides an example of how to read the ammeter scale at different ranges, such as 50 to 100 and 10 to 20.
• 📝 The actual reading is determined by counting the increments from the starting point of the range to the pointer's position.
• 📝 The resistance range multipliers available are: ×1, ×10, ×100, ×1K, and ×10K.
• 📝 The video concludes with examples demonstrating how to apply the formula to get the resistance value for different ranges and actual readings.

Q & A

What is the topic of the lesson conducted by Ronald A. Gonzalez?

The topic of the lesson is about ammeter scale reading.

Where is the ammeter scale located on the meter panel?

The ammeter scale is located in the top most part of the meter panel.

How is the scale of an ammeter described in terms of its numerical order?

The scale of an ammeter has a descending order of numbers from left to right.

What is the starting point for reading resistance values on an ammeter?

Reading resistance values starts from zero on an ammeter.

Why are the gaps between numbers on an ammeter scale not equally divided?

The gaps between numbers on an ammeter scale are not equally divided because it is a non-linear scale.

What is the value per line from zero to two on the ammeter scale?

The value per line from zero to two on the ammeter scale is 0.2.

How do you calculate the resistance value when using an ammeter?

The resistance value is calculated by multiplying the actual reading by the resistance range or multiplier.

What are the different multipliers or resistance ranges available on an ammeter?

The different multipliers or resistance ranges available are: times one, times 10, times 100, times 1K, and times 10K.

What is the formula to get the resistance value as mentioned in the script?

The formula to get the resistance value is: Resistance value = Actual reading multiplied by Resistance range or multiplier.

In the example provided, what is the actual reading when the pointer is between 50 and 100 on the scale?

The actual reading when the pointer is between 50 and 100 on the scale is 65 ohms.

What is the result of the actual reading of 65 ohms when multiplied by the 10K multiplier?

The result of the actual reading of 65 ohms when multiplied by the 10K multiplier is 650k ohms.

Outlines

00:00

📏 Understanding Ammeter Scale Reading

In this segment, the instructor, Ronald A. Gonzalez, introduces the concept of ammeter scale reading. He explains that the scale is located at the top of the meter panel and is arranged in descending order from left to right. The instructor clarifies that readings start from zero and increase to infinity, and the scale is non-linear, meaning the gaps between numbers are not equal. He details how to read the values: from 0 to 2, each line represents an increase of 0.2; from 2 to 10, each line represents an increase of 0.5; from 10 to 20, each line represents an increase of 1; from 20 to 50, each line represents an increase of 2; from 50 to 100, each line represents an increase of 5; and from 100 to 200, each line represents an increase of 20. The instructor also explains how to select the appropriate multiplier or resistance range using the selector knob, which includes options like times one, times 10, times 100, times 1K, and times 10K. He provides a formula to calculate the resistance value, which is the actual reading multiplied by the resistance range or multiplier.

05:01

🔍 Practical Examples of Ammeter Scale Reading

The second paragraph provides practical examples to demonstrate how to read the ammeter scale. The instructor uses a pointer on the scale to show how to read values. For a pointer between 50 and 100, where each line represents a value of 5, the actual reading is determined to be 65 ohms. The instructor then shows how to multiply this reading by different ranges to get the resistance values: 65 ohms multiplied by 10 ohms equals 650 ohms, by 100 ohms equals 6.5 K ohms, by 1K ohms equals 65K ohms, and by 10K ohms equals 650K ohms. In the second example, the pointer is between 10 and 20, with each line representing a value of 1. The actual reading is 12 ohms, which when multiplied by different ranges, results in 120 ohms, 1.2 K ohms, 12 K ohms, and 120K ohms respectively. These examples illustrate the process of reading the ammeter scale and calculating the resistance values based on the selected range.

Keywords

💡Ammeter

An ammeter is an instrument used to measure the current flowing through an electrical circuit. In the context of the video, the ammeter is used to demonstrate how to read scales, particularly for measuring resistance. The script mentions an example of an ammeter scale located at the top of the meter panel, which is crucial for understanding the non-linear scale readings.

💡Scale Reading

Scale reading refers to the process of interpreting the values indicated on a measuring instrument's scale. The video's theme revolves around teaching how to read an ammeter scale, which is non-linear and requires understanding the value increments between different marks on the scale.

💡Non-Linear Scale

A non-linear scale is one where the intervals between the markings do not represent equal increments of the measured quantity. The video explains that the ammeter scale is non-linear, with values increasing at different rates, such as 0.2, 0.5, 1, 2, 5, and 20, depending on the range being read.

💡Resistance

Resistance is a property of materials that opposes the flow of electric current. The video's primary focus is on how to read resistance values using an ammeter, which is essential for electrical measurements and troubleshooting.

💡Multiplier

In the context of the video, a multiplier is used to adjust the scale of the ammeter to measure higher resistance values. The script lists multipliers such as times one, ten, hundred, one thousand (1K), and ten thousand (10K), which are crucial for obtaining accurate resistance readings.

💡Resistance Range

Resistance range refers to the different settings on an ammeter that allow it to measure a wide variety of resistance values. The video script explains how to select the appropriate range using the selector knob to measure high resistance values accurately.

💡Actual Reading

Actual reading is the raw value observed on the scale of an instrument before any adjustments are made. The video provides examples of how to calculate the actual reading from the ammeter scale, which is then multiplied by the resistance range to get the true resistance value.

💡Formula

The formula mentioned in the video is used to calculate the resistance value from the ammeter's reading. It is defined as 'resistance value equals actual reading multiplied by resistance range or multiplier.' This formula is central to understanding how to interpret the readings from the ammeter.

💡Selector Knob

The selector knob is a control on the ammeter used to select the appropriate resistance range or multiplier. The video script emphasizes the importance of using the selector knob to ensure that the ammeter is set to the correct range before taking a measurement.

💡Ohms

Ohms is the unit of electrical resistance. The video script uses ohms to illustrate how resistance values are read from the ammeter and calculated using the formula provided. Understanding ohms is fundamental to grasping the concept of electrical resistance measurement.

💡Example

Examples in the video script are used to demonstrate how to apply the concepts taught, such as reading values from the ammeter scale and calculating resistance using the formula. These examples are practical applications of the理论知识 and help viewers understand how to use an ammeter in real-world scenarios.

Highlights

Introduction to ammeter scale reading

Ammeter scale is non-linear with descending order of numbers

Reading resistance values from right to left

Scale values are not equally divided

Value per line from zero to two is 0.2

Value per line from 2 to 10 is 0.5

Value per line from 10 to 20 is 1

Value per line from 20 to 50 is 2

Value per line from 50 to 100 is 5

Value per line from 100 to 200 is 20

Value per line from 200 to 500 is 100

Explanation of multipliers for high resistance values

Formula to calculate resistance value

Example of calculating resistance with a 10K multiplier

Explanation of resistance range selection

Example calculation for a pointer at 50-100 scale

Example calculation for a pointer at 10-20 scale

Transcripts

good afternoon class my name is Ronald A

Gonzalez your daily teacher or today

[Music]

our topic for today is all about amateur

scale reading

I have an example of ammeter scale

as you can see the scale of ammeter is

located in the top most part of the

meter panel you have noticed a

descending order of number from left to

right in practice reading

values only start from zero

therefore

we will read resistance values from

right to left which is 0 to Infinity

since we will read resistance values

from right to left C to it that the gaps

between numbers are not equally divided

because the scale of ammeter is a

non-linear scale each scale has a value

with respect to its nearest number

now let's read the value per line of

scale of ammeter from zero to two the

value per line is

0.2 each line you need to add 0.2

0.2 0.4 0.6

0.81 1.2 1.4 1.6 1.8 and 2.

from 2 to 10 the value per line is 0.5

each line you need to add

0.5 to 2.5 3 3.5 or

4.5

6.5 7

7.58

8.59 9.5 and lastly 10.

next value per line from 10

to 20 the bar Loop per line is 1.

each line you need to add one

10 11 12

14 15 15

16 17 18 19

20.

next value per line

from

20 to 50 the value per line is 2. each

line you need to add two

twenty twenty two

24 26

28 30 32

34

36 38 40 42 44

46 48 and lastly 50. next value per line

from 50

to 100 the value per line is 5. each

line you need to add 5

[Music]

50 55 60

65 70 75 80 85 90 95

and lastly 100

and the next value per line

from

100 to 200 the value per line is 20.

each line you need to add

20. for example

100

120

140

160

180 and 200.

the next value per line from 200

to 500 the value per line is 100

each line you need to add 100

for example 200

[Music]

300

400 and 500.

[Music]

example of

ometer scale by the way class if you're

going to test the high value of

resistance you need to select the

multiplier or resistance range using the

selector knob and these are the

following multiplier

times one times 10 times 100 times 1K

and lastly times 10 K

I have a formula to get the resistance

value

resistance value is equal to actual

reading multiplied by resistance range

or D multiplier for example the actual

reading is 20 ohms multiplied by 10K 10K

ohms the answer is 200k ohms

[Music]

now let's proceed to the example example

number one

a pointer pointing in the scale of 50 to

100 the volume per line is 5 from 50

each line you need to add 5 50 55 60 65

therefore the actual reading is 65 ohms

now let's multiply it to the given range

65 ohms multiply by 10 ohms is equal to

680 ohms 65 ohms multiplied by 100 ohms

is equal to 6.5 K ohms 65 ohms

multiplied by 1K ohms is equal to

65k ohms and lastly 65 ohms is equal

multiplied by

10K ohms

is equal to

650k ohms

sample number two the pointer pointing

in a scale of 10 to 20. the value per

line is 1 from 10 each line you need to

add 1 10 11 and lastly 12 so therefore

the actual reading is 12 ohms now let's

multiply it to the given range 12 ohms

times 10 ohms is equal to 120 ohms

12 ohms times 100 ohms is equal to 1.2 K

ohms and 12 ohms multiplied by 1K ohms

is equal to 12 K ohms and lastly 12 ohms

multiplied by 10K ohms is equal to

120k ohms

foreign

[Music]