Decagon Devices, Measuring Instruments, models:

AccuPAR LP-80	Operator'S Manual
AquaLab 4TE	Installation Qualification/Operational Qualification Protocols And Instructions
KD2 Pro	Operator'S Manual
MPS-2	Operator'S Manual
Pawkit	Operator'S Manual
SC-1	Operator'S Manual
WP4C	Operator'S Manual