Compliance with regulations WD325 COD reactor is used to digest closed micro reflux COD vial and can meet USEPA 410. 4. It is easier and safer than traditional open macro reflux method. Special COD program Just press start/stop button, and the reactor will start to heat up to 150℃ and keep for 2-hour countdown then shut down automatically with 10-sec audio alarm. 3 additional program settings Temperature range setting 60℃ - 200℃ and timer from 1 - 999. 3 Built-in additional heating program settings available for users to store and execute as needed. Auto shut off and audio alarm WD325 can stop heating, and then shut off automatically with audio alarm when every program is completed.