In one embodiment, a sampling device has first and second detachable body parts defining a fluid flow path. The first body part defines a fluid inlet of the fluid flow path and the second body part defines a fluid outlet of the fluid flow path. A diameter of a portion of the fluid flow path is enlarged to receive and retain a tubular sampling coupon that further defines the fluid flow path. The tubular sampling coupon may be of a type having first and second coupon body parts mated along a long axis. The tubular sampling coupon is of a size and shape to be received and retained within a fluid flow path of a sampling device, wherein the tubular sampling coupon further defines the fluid flow path. Systems and methods using the sampling device and sampling coupon are also disclosed.