Measuring and checking (supervision) apparatus and instruments, including an analyzer enabling the oil and gas processing industries to conduct measurements, inspections and checks; environmental monitoring sensors; gas sensors; laser diode gas sensors enabling the detection of traces of a first gas inside a second for an application in the field of environmental monitoring; environmental monitoring sensors for use in detecting traces in a gaseous environment; environmental monitoring sensors for use in detecting humidity in natural gas or other gases; environmental monitoring sensors enabling hydrogen sulfide (H2S) to be detected in natural gas or other gases; environmental monitoring sensors enabling carbon dioxide to be detected in natural gas or other gases; parts and accessories for the aforesaid goods; software for environmental monitoring applications; software for sensor data characterization; software for controlling a trace gas detection sensor; software for data checking (supervision) and acquisition for obtaining data, checking and monitoring transfer measurements; software for obtaining automated and on-demand intelligence, related to field monitoring devices; industrial process monitoring software; petrochemical equipment monitoring software; software for controlling a variety of remote sensors to monitor the level of trace gases in a gaseous environment