Walkthrough assessments may also reveal the need for a full air audit using data loggers to measure operating current and provide an insight of the compressed air utilisation within a given system. Data loggers are attached to the compressor for a minimum of 7-14 days in order to observe and record any trends and demand fluctuation throughout working week days as well as the weekend. Results of such audits can provide a good understanding of the actual compressed air usage over a period of time, identify peaks and troughs in the air demand pattern and identify ways to improve the overall efficiency of the system. Other than helping to properly size an air compressor, air audits can also identify leaks in the installation, especially during night or weekend plant shutdown periods.