What are the advantages and disadvantages of using voltage drop as an NDT indicator?

1 What is voltage drop?

Voltage drop is the difference in voltage between two points in an electrical circuit or a material. It occurs when electrical current encounters resistance, which reduces the amount of energy available to the load. Resistance can be caused by various factors, such as the length, cross-section, temperature, and composition of the conductor or the material. The higher the resistance, the higher the voltage drop, and vice versa.

2 How is voltage drop measured?

Voltage drop can be measured by using a voltmeter or a multimeter, which are devices that measure the electrical potential difference between two points. The voltmeter or multimeter is connected to the two points of interest, and the voltage drop is displayed on the screen or the dial. The voltage drop can also be calculated by using Ohm's law, which states that voltage equals current times resistance (V=IR). By knowing the current and the resistance of the circuit or the material, the voltage drop can be derived.

4 What are the disadvantages of using voltage drop as an NDT indicator?

Using voltage drop as an NDT indicator has some drawbacks, such as its dependence on external factors like temperature, humidity, and contact quality, which can cause errors or variations in the voltage drop measurements. Additionally, it is limited by the accessibility and availability of the points of measurement, which may be difficult or impossible to reach or connect in some cases. Lastly, it is not specific or diagnostic, as it does not provide information on the type, location, size, or severity of the defect. Therefore, further investigation or testing by other NDT methods may be necessary.

5 How to use voltage drop as an NDT indicator effectively?

Using voltage drop as an NDT indicator effectively requires following some best practices. It is important to choose the appropriate voltmeter or multimeter for your application, and ensure it is calibrated and functioning properly. Additionally, select the points of measurement carefully, making sure they are clean, dry, and secure to avoid false readings or poor connections. It is also necessary to compare the voltage drop measurements with the expected or normal values for your material or component, and look for any significant deviations or anomalies that indicate a problem or a flaw. Lastly, verify and validate your results by using other NDT methods or techniques such as visual inspection, ultrasonic testing, or eddy current testing to confirm or rule out the presence and nature of the defect, corrosion, crack, or flaw.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?