What is the term that indicates the total amount the seller receives from the sale of a product in a particular time period?

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tender to it by Seller, Seller may, at its option, to that extent suspend the extraction of helium-gas mixture in either or both of the plants until Buyer notifies Seller that Buyer is ready to resume taking delivery of additional helium-gas mixture. During such period the volume which shall be considered as extracted and tendered to Buyer shall be determined as follows:

(a) To the extent that either or both of the plants continue to extract helium-gas mixture during such period and measure such mixture in accordance with the provisions of Article X, the results of such measurement shall apply.

(b) To the extent that either or both of the plants suspends the extraction and/or measurement of helium-gas mixture during such period, the volumes of unmeasured helium-gas mixture which shall be considered as extracted and tendered to Buyer shall be a computed volume, based upon the volume of helium in natural gas available for processing by the plant or plants during the suspension and the recovery factor experienced during the five (5) day period of normal operations next preceding the suspension.

ARTICLE III. EFFECTIVE DATE AND TERM

3.1 This agreement shall become effective at eight o'clock a.m. Central Standard Time on the date of this agreement and, unless sooner terminated as hereinafter provided, shall expire as to the Dumas Plant and the CactusDumas Pipelines at eight o'clock a.m. Central Standard Time on October 29, 1977, and shall expire as to the Sherman Plant at eight o'clock a.m. Central Standard Time twenty-two (22) years after the dạte of this agreement, with the understanding and agreement, however, that such expiration or termination shall not affect the right of the Seller to the monies due or to become due Seller from Buyer under and pursuant to the terms and provisions of this contract and unpaid at the time of such expiration or termination.

ARTICLE IV. FACILITIES

4.1 Seller agrees to construct, or cause to be constructed, with reasonable promptness and diligence, and at its own risk and expense, the following facilities:

(a) a plant near Seller's Sherman Gasoline Plant in Hansford County, Texas, wbich shall be capable of processing approximately two hundred (200) MMcf of natural gas a day for the extraction of helium in a manner to recover not less than ninety (90) per cent by volume of the helium in the natural gas so processed ;

(b) a plant near Seller's Dumas Gasoline Plant in Moore County, Texas, which shall be capable of processing approximately two hundred seventy-five (275) MMcf of natural gas a day in a manner to recover not less than ninety (90) per cent by volume of the helium in the natural gas so processed ; and

(c) a pipeline system consisting of one pipeline for the purpose of transporting natural gas from Phillips Chemical Company's Cactus Plant to Seller's Dumas Plant and one pipeline for the purpose of transporting

residue gas from Seller's Dumas Plant to said Cactus Plant. Seller estimates that such facilities will be completed and ready to make the initial delivery of helium-gas mixture hereunder within fourteen (14) months after the effective date of this contract and Seller agrees that it will be ready to make the initial delivery hereunder within twenty (20) months after the effective date of this contract.

4.2 Buyer agrees to construct, or cause to be constructed, with reasonable promptness and diligence, and at its own risk and expense, a pipeline for the purpose of receiving the helium-gas mixture tendered for delivery by Seller hereunder, and Buyer agrees to be prepared within fourteen (14) months after the effective date of this contract to receive the helium-gas mixture tendered for delivery by Seller.

4.3 Each party shall have exclusive control over the facilities which it shall construct or cause to be constructed pursuant to this Article IV and shall operate and maintain, or cause to be operated and maintained, the respective facilities throughout the period this contract is applicable thereto. 4.4 It is expressly understood and agreed by both parties hereto that the helium content and volume of natural gas available for processing in Seller's plants will vary from time to time depending upon the production and availability of such natural gas from various wells and fields and upon the requirements for delivery of such gas to fulfill the needs of domestic and industrial fuel gas consumers. Specifically recognizing this situation, Seller agrees to use its best efforts to maintain a supply of natural gas and to operate its plants to recover the maximum quantity of helium consistent with the foregoing.