Gas Technician 3 (G3) License Practice Exam

When a digital ohmmeter is connected across an open circuit, it typically displays "OL," which stands for "Open Loop." This indicates that there is no path for current to flow due to the open circuit condition. In terms of resistance measurement, an open circuit signifies that the resistance is infinitely high because the two points are not connected, but most digital multimeters represent this condition as "OL" rather than showing a numerical value like infinity or a zero.

The "OL" display alerts the user that there is an interruption in the circuit and no continuity exists between the test points. It is a crucial feature that helps to quickly identify circuits that are not complete, allowing technicians to troubleshoot effectively. While the term "∞" would theoretically denote infinite resistance, it is not used by all digital multimeters, making "OL" the more universal and recognized response in practice when dealing with open circuits.