This report describes the operation theory, installation procedures and operation guidelines for instrumentation selected to monitor changes in internal pavement moisture and thermal regimes, frost/thaw conditions, and external climate at test sections in the long-term pavement performance seasonal monitoring study. The instrumentation includes time domain reflectometry to measure moisture content of unbound materials, thermistor sensors to measure pavement temperature gradients and air temperature, electrical resistivity probes to measure frost locations, a piezometer to measure the depth of ground water table and tipping-bucket rain gauge to measure precipitation. These measurements of the external climate and the resulting changes in the pavement material will be coupled with monthly or more frequent deflection measurements,seasonal roughness measurements, elevation profile and distress surveys to study the cause and effects of seasonal changes in pavement structural response. Guidelines and procedures for the collection of these data are also described in this report.