The London-based official will arrive at Sixfields Stadium for his 23rd game of the season and 13th in Sky Bet League Two following his promotion to the National List of Referees after two campaigns on the National League.
His first game in the EFL came on August 3rd when he issued four caution in Exeter City's 1-0 home win over Macclesfield Town, while he showed four yellow cards in AFC Wimbledon's 1-0 home win over Portsmouth a week ago in what was his first-ever League One match. His second swiftly followed on Wednesday night when he oversaw Peterborough United's 4-0 home win over Accrington Stanley, handing out three cautions.
Purkiss has also been handed fourth official roles in Championship games so far this season, most notably at Fulham versus Blackburn Rovers while he was back at Craven Cottage two weeks later in the same capacity for the encounter against Nottingham Forest.
His latest encounter came in League Two at the weekend as he oversaw Stevenage's home match with Plymouth Argyle which ended in a 2-1 victory for the Pilgrims. He issued one yellow on the day.
Despite being only 21 games into his National List career, he's already taken charge of the Iron twice previously - the slender 1-0 home defeat to Carlisle United back at the end of August and the 1-1 draw at Salford back in October. He issued seven cautions in the first game, six of which to the Cumbrians, followed by just one to the Ammies in the second encounter.
He's taken charge of two Cobblers games in the past, both of which this season also. He last took charge of them in the 4-0 away hammering at Crawley Town on Boxing Day. He's shown four yellow cards across the two games.
Last season, he took charge of a total of 19 matches in the National League, showing 39 yellow cards and two reds. So far in this campaign, he's shown 66 yellow cards and no reds in 22 games.
On Tuesday, he will be assisted by Thomas Harty and George Byrne, while Richie Watkins will assume the role of fourth official.
PREVIOUS SCUNTHORPE UNITED ENCOUNTERS
| DATE | COMP | MATCH | Y | R |
| Oct 26, 2019 | LG 2 | Salford City 1-1 Iron | 1 | 0 |
| Aug 31, 2019 | LG 2 | Iron 0-1 Carlisle United | 7 | 0 |
PREVIOUS NORTHAMPTON TOWN ENCOUNTERS
| DATE | COMP | MATCH | Y | R |
| Dec 26, 2019 | LG 2 | Crawley Town 4-0 Northampton Town | 2 | 0 |
| Oct 8, 2019 | EFL T | Cambridge United 0-1 Northampton Town | 2 | 0 |
