Recreational Vehicle (RV) Technician Practice Test

What action should you take if an analog voltmeter's needle deflects to the right and off the scale?

1. Change to a lower voltage scale

2. Change to a higher voltage scale

3. Calibrate the voltmeter

4. Replace the voltmeter

The correct answer is: Change to a higher voltage scale

When using an analog voltmeter, if the needle deflects to the right and goes off the scale, this indicates that the voltage being measured exceeds the maximum limit of the current scale being used. In such a situation, the appropriate action is to change to a higher voltage scale. By selecting a scale that can accommodate a larger voltage range, you ensure that the voltmeter can accurately measure the voltage without the needle exceeding its capacity, which could cause damage to the meter or provide misleading readings. This action is crucial for protecting the instrument and obtaining correct voltage measurements. It is also important to remember that an analog voltmeter displays the voltage based on the deflection of a needle; hence, if it goes off the scale, it signifies that the range limit has been surpassed. Adjusting to a higher scale allows for accurate readings and effective troubleshooting in electrical systems, which is vital for RV technicians.