Dehumidifiers should be removed when you can no longer justify having them on a job. Check the Specific Humidity (grains of weight of water vapor in one pound of air) of the air going into your dehumidifier compared to the Specific Humidity of the air coming out of your dehumidifier. That difference is called grain depression. When the grain depression is close, your dehumidifier is not removing much moisture from the air and should be removed. Also check the Specific Humidity of the unaffected areas of the job, I would expect the Specific Humidity will be lower in your drying chamber.
As others have said use your moisture meters to insure you are putting moisture in the air, wet materials are drying and there is no trapped moisture in any affected materials.