Opening batsman Adams began his innings at 11.30am on Friday and had reached 87 before he was finally dismissed at 3.10pm on Sunday.
Bad light plagued the clash for the second successive day – with only 28 overs bowled before time was called with Hampshire on 241 for four.
Hashim Amla weighed in with his first half-century for the county – notching 52 from 93 deliveries.
But with just 88 overs completed across the first three days, a draw is the only plausible outcome when the sides resume on Monday.
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Adams said: ‘It was a hard slog. It was possible to score when they missed but the ball was still offering something when it was 70 overs old.
‘It always felt like there was something in it.
‘I was happy how it went personally and Hash batted beautifully but it is frustrating in the sense we were probably on our way to a well above-par score.
‘There have certainly been times when it has been dark but on Saturday we probably came off when it wasn’t quite so bad and that is unfortunately when the umpires took the (benchmark) reading.
‘Whether we could have pushed for anything else in the game other than a draw and bonus points, I don’t know but the forecast for today is not great.’
Adams, 37, was buoyed by his own form after another winter of hard work.
‘I have been tinkering with my stance in the winter,’ he added.
‘I certainly wouldn’t tell my kids to bat like me!
‘Some of it is for ease of comfort and getting two eyes to the ball but not much has changed when the ball is released.’
Meanwhile, Sam Northeast expects to be sidelined for at least a month after injuring the little finger on his left hand on the eve of the game.
The former Kent batsman, who struck 129 against Surrey the previous week, said: ‘It was the last catch in training the day before the game, so it was hugely disappointing, especially after last week.
‘I had got that score and wanted to build on it. When you move to a new club you want to keep building on that.
‘Hopefully I can get back reasonable quickly. I am looking at a hand specialist and maybe surgery next week. Hopefully I will be back in a month or six weeks’ time.’