Delta F Corp., Woburn, MA, offers literature on its DF 140 oxygen analyzer. The DF140 incorporates a nondepleting sensor and does not require frequent recalibrations, rebuilding, or replacement. Optional NEMA 4X and NEMA 7 remote sensor enclosures are available for use in Class I, Div. 1 and 2 areas. Each analyzer is calibrated to NIST standards.