Illuminance Illuminance sensor, example units = lx 3301 urn:oma:lwm2m:ext:3301 1.0 1.0 Multiple Optional Sensor Value R Single Mandatory Float Last or Current Measured Value from the Sensor. Min Measured Value R Single Optional Float The minimum value measured by the sensor since power ON or reset. Max Measured Value R Single Optional Float The maximum value measured by the sensor since power ON or reset. Min Range Value R Single Optional Float The minimum value that can be measured by the sensor. Max Range Value R Single Optional Float The maximum value that can be measured by the sensor. Reset Min and Max Measured Values E Single Optional Reset the Min and Max Measured Values to Current Value. Sensor Units R Single Optional String Measurement Units Definition.