Volumetric flow meters, volumetric flow controllers, mass flow meters, and mass flow controllers using a transverse laminar flow assembly are described. The flow assembly may be constructed from a plurality of open and/or closed slices or layers stacked upon one another and held together in compression by through bolts or another means. Meter or flow controller accuracy may be aided by use of flow conditioning features preceding an axial bore of the transverse flow assembly including one or more of a deflector, filter and nozzle.