(a) General rule.--Where the contract requires payment before inspection nonconformity of the goods does not excuse the buyer from so making payment unless:
(1) the nonconformity appears without inspection; or
(2) despite tender of the required documents the circumstances would justify injunction against honor under this title, including section 5109(b) (relating to conditions for injunction).
(b) Effect of payment on rights of buyer.--Payment pursuant to subsection (a) does not constitute an acceptance of goods or impair the right of the buyer to inspect or any of his remedies.