RMLD RMLD-CS™. Image Credit: Heath Consultants Incorporated RMLD-FR™. Image Credit: Heath Consultants Incorporated Heath Consultants was the first to launch a sophisticated methane leak detector based on tunable diode laser absorption spectroscopy (TDLAS), leading to scores of legacy units across the world. The RMLD-IS is a legacy instrument, with thousands of units sold around the world. It contains a couple of interactive components—a signal processing/user interface controller and a transceiver subsystem. Both the Remote Methane Leak Detector – First Responder (RMLD-FR) and the Remote Methane Leak Detector – Complete Solution (RMLD-CS) avoid the need for the individual receiver and transceiver, integrating them into a single hand-held instrument that is portable, lightweight, and rugged for field applications.