Documentation Application Information Case studies, diagrams and tutorials provide detailed information for ONICON flow and BTU meter applications. Manuals Current manual versions for all ONICON products. Catalog Sheets Individual catalog sheets for all ONICON products. CAD Drawings CAD drawings for typical installation, piping and applications for flow meters and BTU meters. Engineering Specifications Written engineering specifications for ONICON flow meters and BTU Meters, ready to insert into your documents. Networking Information Current networking documentation Wiring Diagrams Refer to ONICON Installation manuals for detailed wiring instructions. You may also contact ONICON technical service for system wiring diagrams that show the interconnection between the flow meter and any peripheral device, such as a Btu meter or display module.