ESA Certified Alarm Technician Practice Exam

For accurate voltage measurements, which setting should you avoid?

1. Using the highest voltage range

2. Using the lowest voltage range

3. Using a multimeter

4. Using an analog meter

The correct answer is: Using the lowest voltage range

In voltage measurements, using the lowest voltage range tends to limit accuracy, especially if the voltage being measured exceeds that range. When a multimeter is set to a low voltage range, it can result in the meter saturating or giving inaccurate readings due to exceeding its measurable capacity. This is particularly problematic if the actual voltage falls outside the specified limits of the lowest range, as it could lead to what is known as 'overload' conditions. In contrast, using the highest voltage range can provide a broader scale to detect the maximum voltage without risk of exceeding the meter’s limits. Multimeters themselves are designed to handle various ranges of voltage effectively, and analog meters can provide specific insights as well, provided they are used appropriately. Therefore, for accurate voltage measurements, selecting a range that accommodates the expected voltage is critical, thus avoiding the lowest setting when possible.