Hydro has a long history of using the ISO 17499 equivalent temperature method [1] for monitoring anode baking levelsAnode baking level. It gives the baking level for single anodesAnode, baking statistics for lots, or series, of anodesAnode and can also be used to monitor heat loads by position in the furnacesFurnace. The common scale helps operations control baking, and the quality of baking can be monitored across plants, past and future. In practice, a portion of a reference green coke in a crucible is sent with the anodeAnode through the baking furnaceFurnace. After cooling, the calcined coke Lc-value is measured, and the baking levelBaking level control found from a calibrated scale prepared using the reference coke. As the green coke is a consumable, stock will be consumed and depleted. Several methods are discussed that can help establish and, importantly, maintain the calibrated scale. The paper describes how suitable green cokes are found and the challenges with their certification. Over the last 15 years, Hydro has worked with Rain CarbonCarbon to successfully introduce two new green cokes to support its global baking operations.