The flat flange bell is used for tests with a vacuum experimental plate (vacuum chamber). The bell has a ground flange and a ground joint for the insertion of measuring equipment.– Tight closure due to standard ground joint – Top opening allows connection of additional equipment – Fired-on, highly durable white ceramic – – The flat flange bell is used for tests with a vacuum experimental plate (vacuum chamber). The bell has a ground flange and a ground joint for the insertion of measuring equipment.– Tight closure due to standard ground joint – Top opening allows connection of additional equipment – Fired-on, highly durable white ceramic – –