Secretary of State Mike Coffman cleared the way for 47 counties to use their optical scanners to count paper ballots in this year's elections,
Mesa County was not one of them.
Coffman decertified the scanners back in December citing accuracy concerns.
Scanners made by Hart Intercivic have been recertified. But Mesa County and Jefferson County use scanners made by ES&S and Coffman did not recertify them.
Mesa County officials are on their way to Denver to have the scanners tested.
On Thursday ballots will be marked and then on Friday scanned through the county's machines to see if they can correctly scan and tabulate multiple ballots.
County officials say they are confident the equipment will pass.