In the context of gas foil bearings, monitoring the lift-off condition remains a significant challenge. Although some techniques have been proposed to detect this phenomenon, no methodology has yet proven reliably effective and widely adopted, especially in commercial applications. To address this gap, the present study analyzes signals from accelerometers and position sensors in both the time and frequency domains to evaluate which approach provides the highest accuracy in detecting the lift-off condition. The results indicate that both sensors perform very well in the time domain. However, in the frequency domain, accelerometers show markedly better results than position sensors.