(a) A mortgage may be discharged upon the record thereof by the recorder in whose custody it shall be whenever there shall be presented to him a certificate executed by the mortgagee, his personal representatives or assigns, acknowledged or proved and certified as prescribed in chapter 3 of this title to entitle a conveyance to be recorded, specifying that the mortgage has been paid or otherwise satisfied or discharged.
(b) Every such certificate and the proof or acknowledgment thereof shall be recorded at full length, and a reference shall be made to the book and page containing such record in the minute of the discharge of such mortgage made by the recorder upon the record thereof.