ADC	analog-to-digital converter
CAPS	cavity-attenuated phase shift spectrometer/spectroscopy
CIMS	chemical ionization mass spectrometry
CLD	chemiluminescence detector/detection
CW	continuous wave
DAC	digital-to-analog converter
DAQ	data acquisition
DFB-QCL	distributed feedback quantum cascade laser
FPGA	field-programmable gate array
FSR	free spectral range
iCW	intermittent continuous wave
LAS	laser absorption spectroscopy
LOD	limit of detection
MCT	mercury cadmium telluride
MFC	mass flow controller
mid-IR	mid-infrared
Mo	molybdenum
MPC	multipass cell
OPL	optical path length
PCB	printed circuit board
PFA	perfluoroalkoxy alkane
ppb	part per billion by volume
ppt	part per trillion by volume
PTFE	polytetrafluoroethylene
QCLAS	quantum cascade laser absorption spectrometer/spectroscopy
TEC	thermoelectric cooling
VOCs	volatile organic compounds