Gas Fitter Practice Test

How should an inline ammeter be connected for accurate measurement?

1. In series with the device being checked

2. In parallel with the device being checked

3. With the system power off

4. Across the load

The correct answer is: In series with the device being checked

An inline ammeter should be connected in series with the device being checked to ensure accurate measurement of the current flowing through that device. When an ammeter is connected in series, it becomes part of the circuit, allowing it to measure the total current that passes through the device. This configuration is essential because ammeters are designed to measure current flow, which is only possible when they are part of the circuit through which that current flows. Connecting an ammeter in parallel with the device or across the load would not provide a true measurement of the current through the device, as it would create an alternate path for the current. In such scenarios, the ammeter could also be damaged due to high current flow, leading to inaccurate or ineffective readings. Ensuring that the system power is off is critical before making connections, but it doesn’t pertain directly to the ammeter's connection for measurement purposes. Thus, the proper and safe method is to connect the ammeter in series with the device being measured.