Pset_SpatialGeoObsSensor Properties describing sensors used for geoscience observations. IfcSensor IfcSensor PlacementType Indicates the purpose of the sensor placement. MONITORING SURVEY MONITORING Permanently installed for an extended time period for monitoring purposes SURVEY Tentatively installed/placed for a short-time of period. MeasurementStartTime Measurement/Monitoring period or point in time - start. MeasurementEndTime Measurement/Monitoring period or point in time - end.