Final answer:
The minimum CSA of a conduit body for 1-inch conduit must be determined using the NEC standards or manufacturer's specifications, and the internal volume of the conduit body should be at least equal to the CSA of the conduit attached to it.
Step-by-step explanation:
The minimum Cross-Sectional Area (CSA) of a conduit body used with 1-inch conduit is determined by the conduit body size specified by the manufacturer and the National Electrical Code (NEC) standards. It is important to refer to the NEC or manufacturer's specifications to find the exact CSA required for a conduit body for 1-inch conduit. The CSA for 1¼-inch conduit is provided as 1.5, but without the NEC table or manufacturer's guidelines, we cannot determine the CSA for 1-inch with the same certainty. As a rule, however, the internal volume of any conduit body must be at least equal to the CSA of the conduit being attached to it but the specific details do require the relevant standards or tables.