What is the benefit of measuring both direct and reverse current?

In summary, the conversation discusses the benefits of measuring voltage in both directions and how it can nullify the effect of resistance in connecting wires. There is a mention of the importance of verifying measurements and the use of a 4-wire or kelvin connection. However, there is a lack of context and a diagram to fully understand the conversation. Additionally, it is mentioned that measuring in both directions can also help identify stray current in a facility.
  • #1
phymath7
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TL;DR Summary
Why do we have to measure low resistance (in method of fall of potential )and galvanometer resistance (method of half-deflection ) for both direct and reverse current?
What is it's benefit?
 
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  • #2
Who says we do ? Do you have a reference, some context. a link ?
 
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  • #3
BvU said:
Who says we do ? Do you have a reference, some context. a link ?
I don't have reference from any higher level practical book but from a local writter of my country.So I am not providing reference as I think that won't be considered worthy.But my teacher said that it's done to nullify the effect of resistance of the connecting wires.I am not sure how that works.
 
  • #4
phymath7 said:
I don't have reference from any higher level practical book but from a local writter of my country.So I am not providing reference as I think that won't be considered worthy.But my teacher said that it's done to nullify the effect of resistance of the connecting wires.I am not sure how that works.
That doesn't make sense to me either. It would be a good way of identifying voltages that don't depend on the current direction, like a voltage offset from a battery, or voltages that depend too much on polarity, like a diode in the circuit. It's also just a good sanity check of the instrument and the circuit being tested. The answer should usually be the same, if it's not, more investigation is needed.

In general, good lab practice is to try and verify your measurements with a slightly (or vary) different setups that shouldn't matter, because sometimes your assumptions, instruments, or measurements are wrong.

BTW, if you do want to correct for the lead resistance, you can just measure "0" resistance by putting the probes on the same conductor and subtract that from your measurement. An even better way is to do a 4-wire or kelvin connection, which requires a bit more than just simple ohm-meter.
 
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  • #5
phymath7 said:
But my teacher said that it's done to nullify the effect of resistance of the connecting wires.I am not sure how that works.
You haven't given us adequate context to understand what's being said. What connecting wires? What do they connect? Can you show us a diagram?
 
  • #6
What @DaveE said. The 'both directions' process will also indicate the presence of 'stray current' - that isn't uncommon when measuring grounds in a facility with existing energized equipment - it can significantly skew your result if you don't know that it's there. Once identified, it can usually be dealt with arithmetically (or by turning off some equipment).
 

FAQ: What is the benefit of measuring both direct and reverse current?

What is the benefit of measuring both direct and reverse current in electronic components?

Measuring both direct and reverse current in electronic components helps to understand their behavior under different conditions. This can reveal issues like leakage currents, reverse breakdown voltage, and overall integrity of the component, ensuring it operates reliably within its specified parameters.

How does measuring both direct and reverse current improve the accuracy of a circuit's performance analysis?

Measuring both direct and reverse current provides a comprehensive view of a circuit's performance. It allows for the identification of anomalies and ensures that components are functioning correctly in both polarities, thereby improving the overall accuracy and reliability of the performance analysis.

Why is it important to measure reverse current in diodes and transistors?

Measuring reverse current in diodes and transistors is crucial because it helps in determining the reverse leakage current and the reverse breakdown voltage. This information is vital for ensuring that these components will not fail under reverse bias conditions, thus maintaining the stability and reliability of the circuit.

Can measuring direct and reverse current help in identifying faulty components?

Yes, measuring direct and reverse current can help in identifying faulty components. Discrepancies in expected current values, such as higher than normal reverse current, can indicate issues like damaged junctions or impurities within the component, allowing for early detection and replacement of faulty parts.

What role does measuring both direct and reverse current play in quality control?

In quality control, measuring both direct and reverse current ensures that electronic components meet their specified performance criteria. It helps in detecting manufacturing defects, ensuring that only components that pass stringent tests are used in final products, thereby enhancing overall product reliability and customer satisfaction.

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