Measurement of High Resistance by Megohm Method

TL;DR

Learn how the Megohm method measures high resistances accurately using a modified Wheatstone bridge setup.

Transcript

hello friends in this video we will study the make ohm method which is used for the measurement of high resistances high resistances are those resistance which are greater than the value of 100 kilo ohm or 0.1 mega ohm so let us start with our topic as i have said that the high resistances are those resistances which are having the resistance value... Read More

Key Insights

• ✋ High resistances, above 100 kilo ohm, are vital in various electrical applications for insulation and accuracy.
• ✋ The Megohm method utilizes a modified Wheatstone bridge with a three-terminal high resistance for precise resistance measurements.
• 📣 Accuracy in measuring high resistances with the Megohm method ranges from 3% for 0.1 mega ohm to 10% for values between 10^4 and 10^6 mega ohms.

Questions & Answers

Q: What defines high resistances in the context of electrical measurement?

High resistances are those exceeding 100 kilo ohm or 0.1 mega ohm, crucial in applications like insulation testing or vacuum tube circuits due to isolation and accuracy needs.

Q: How does the Megohm method improve resistance measurement accuracy?

The Megohm method utilizes a Three Terminal High Resistance and a guard terminal to reduce errors and increase the precision of resistance measurement in high range resistances.

Q: What modifications were made to the Wheatstone bridge for the Megohm method?

The Megohm method includes connecting the guard terminal to the meeting point of key resistances, improving accuracy in measuring high resistances up to 10^6 mega ohms.

Q: What is the significance of using a three-terminal resistance in the Megohm method?

The three-terminal high resistance in the Megohm method, with a guard terminal, allows for more accurate and precise resistance measurements compared to traditional Wheatstone bridge setups.

Summary & Key Takeaways

• High resistances, over 100 kilo ohm, are measured by methods like the Megohm method.

• Megohm resistance examples include insulation resistance and vacuum tubes.

• The Megohm method uses a modified Wheatstone bridge for accurate resistance measurement.