An array of in-field testing equipment can be used to measure temperature, moisture, sound levels, air pollutants, or other criteria. Standardized procedures for taking these measurements are provided in the Performance Measurement Protocols for Commercial Buildings.[7] For example, thermal infrared (IR) imaging devices can be used to measure temperatures of building components while the building is in use. These measurements can be used to evaluate how the mechanical system is operating and if there are areas of anomalous heat gain or heat loss through the building envelope.[8]