答：凭语感和语法,当我阅读到a study时,就感觉此句有误.一般说：so +adj.+a 单数可数名词 that ...
或as +adj.a 单数可数名词 +as.
这是两个句型.
通常都是：a +adj.+可数名词单数.
所以判断,你的detailed前应该还有一个as:
搜索网络,果不其然：
现代大学英语(英语专业)外研版第2册 > Unit 12 > Text A中
exhaustive
adj.彻底的；详尽的；全面的
I believe I have made as detailed and exhaustive a study of his personality and home life as it is possible for any being to make.
这是一个复合句.其中主句是
I believe (that)- 宾语从句.
是一个主谓宾结构.
宾语从句 I have made as detailed and exhaustive a study of his personality and home life as it is possible for any being to make.
分析：
主要结构是：I have made as +adj.a 单数可数名词 +as-比较状语从句.
adj.=detailed and exhaustive
study 研究,是一个可数名词的单数.后跟一个介词短语of his personality and home life 作后置定语.“关于.的一项研究.
as 引导的比较状语从句：it is possible for any being to make.
any being=any person,
意思是“我已经做了一项尽可能详尽的研究”.
全句翻译：
我认为我已经做了一项尽可能详尽的研究.