Description: Period of time from the commissioning of a plant, part of a plant, a component or a line system; Name: service life
Description: passed time period after comissioning of a system, sub-system, component or piping; Name: Operating time 
Description: norm/stipulation describing the explosion protection. The explosion protection type, the device category, the temperature class as well as the device / explosion group are taken from this norm. The type and number of the norm/stipulation with issue year and issue month must be given; Name: Reference norm of the explosion protection