Abstract: A flame ionization detector burner, includes a housing having a generally cylindrical flame cavity therein extending along a generally longitudinal axis of the housing and a housing exterior with intake passageways communicating between the housing exterior and the flame cavity for passing fuel, air and sample flows into the flame cavity and an exhaust passage communicating between the housing exterior and the flame cavity for passing exhaust gasses out of the flame cavity. A burner carried in the housing cavity receiving the fuel, air, and sample flow generates a flame to ionize the sample. An ion collector plate spaced away from the burner carried in the time cavity collects sample ions and provides an electrical output representative of the sample ions to the housing exterior via an electrical feedthrough between the flame cavity and the housing exterior. The housing includes at least two cylindrical sidewalls removably joined together along the general longitudinal axis of the housing.