English to Russian Law/Patents Law (general) Sales Agreement

Добрый день!
Помогите, пожалуйста, перевести "commenced tone" в следующем контексте в предпоследнем предложении:

The Buyer shall be obliged to pay the Price to the Seller for the Goods delivered and to take the Goods over at the Place of Take-Over of the Goods and as of the date of Delivery of the Goods and/or the date of shipment of the Goods as determined in the written confirmation of the Purchase Order. If the Buyer fails to take the Goods over from the Seller at the Place of Take-Over of the Goods and/or on the delivery date of the Goods or on the shipment date of the Goods set in the written confirmation of the Purchase Order, the Seller shall be entitled to store the Goods, at the expenses of the Buyer in the warehouse of the Seller or in the warehouse of any other third party. In the case that the Goods are placed in the Seller’s warehouse, the Seller shall be entitled to charge the costs of the storage to the Buyer in the amount of EUR 15 per each commenced tone of the Goods per each day of storage. In case of the storage of the Goods in a warehouse by a third party, the Seller shall be entitled to charge to the Buyer the costs of the storage charged to the Seller by such third party.

Заранее спасибо!