Direct in-situ carbon potential measurement; high-precision in-situ carbon potential measurement in carburizing atmosphere, with an accuracy of +/- 0.02 wt%C in carburizing atmosphere. When used with an oxygen probe, it can be controlled simultaneously with the carbon potential and nitrogen potential through the UPC Protherm 500/600 controller. The replaceable measurement head allows for quick on-site maintenance. Mooncakes are not only visually appealing but also delicious. Traditional mooncakes are baked, featuring thin wrappers and rich fillings, such as double yolk white lotus paste, five-fruit, red bean paste, ham, etc.