Many newer units or refurbished models have a QR code on the side of the electronics housing that links directly to the digital documentation.
Select the model number of the sensors you are using. 5. Troubleshooting Common Errors flexim fluxus adm 7407 user manual free
The manual would emphasize that the sensor placement is critical. The ADM 7407 uses two transducers (Upstream and Downstream). Many newer units or refurbished models have a