Before preparing a voting machine for an election at which candidates for more than one political party or candidates nominated by petition are to be voted for, written notice must be mailed to the chairman of the local committee of each of the political parties that have certified candidates, stating the time and place where the machines will be prepared. At this time, one representative of each of these political parties must be afforded an opportunity to see that the machines are in proper condition for use at the election. When a machine has been examined by these representatives, it must be locked or sealed with a numbered seal in their presence. The representatives must certify as to the numbers of the machines, that all counters are set at zero (000), as to the number registered on the protective counter, and the number on the seal. When a voting machine has been properly prepared for an election, it must be locked or sealed against voting, and any necessary seals or keys to the machine retained in the custody of the board of voter registration and elections or other electoral board and delivered to the managers of election as provided in this chapter.