Siemens 66BA4-4297-114 Amplifying Relay 4 To 1

Siemens 66BA4-4297-114 Amplifying Relay is a diaphragm-based pneumatic signal amplifier in the 66 series, engineered to take a low-pressure input and produce a higher-pressure output at a 4:1 amplification ratio. The 4297-114 designation identifies this specific diaphragm/assembly configuration within the 12-series 66 amplifying-relay family. This device is used in process-control and instrumentation setups to couple small signal pressures from sensors or controllers to pneumatic actuators or controllers, providing signal conditioning and isolation between control logic and the pneumatic output. The 66BA4 model denotes the 4:1 ratio option, and Siemens documentation notes that input–to–output ratios can be altered by replacing the diaphragm ring and output diaphragm assembly, allowing different amplification configurations without replacing the entire unit. Typical applications include signaling and control in legacy pneumatic control loops and instrumentation panels where a stable, amplified pneumatic signal is required to drive downstream control elements.