In critical circumstances where delay would cause damage which it would be difficult to repair, a Member may take a provisional safeguard measure pursuant to a preliminary determination that there is clear evidence that increased imports have caused or are threatening to cause serious injury. The duration of the provisional measure shall not exceed 200 days, during which period the pertinent requirements of Articles 2 through 7 and 12 shall be met. Such measures should take the form of tariff increases to be promptly refunded if the subsequent investigation referred to in paragraph 2 of Article 4 does not determine that increased imports have caused or threatened to cause serious injury to a domestic industry. The duration of any such provisional measure shall be counted as a part of the initial period and any extension referred to in paragraphs 1, 2 and 3 of Article 7.