An emitter unit to be integrally bonded to an internal surface of a conduit (30) and comprising a housing 1, including a flowpath, and having a housing inlet (19a) adapted to communicate with the interior of the conduit (30) and a flowpath inlet portion (11a), and a housing outlet (26) adapted to communicate with a flowpath outlet portion (24a) and a conduit outlet (31); wherein the housing has further formed in an outer surface a partially covered elongated inflow channel (17a, 17b) adapted to be exposed to the interior of the conduit (30) and to communicate with the housing inlet (19a), an array of filter baffles (18a, 18b) being formed along the length of the inflow channel (17a, 17b). <IMAGE>
