Key benefits Dual-output sensing: provides both a digital switching output (DO, TTL) for threshold alarms and an analog output (AO) for continuous concentration monitoring. Use one module for alerting and data logging without extra converters. Direct compatibility with control systems: the TTL switching output is active low and can be connected directly to microcontrollers or relay modules, reducing wiring and interface hardware. Fast, reliable response: analog output voltage changes with concentration and the sensor offers fast response and recovery, enabling timely detection and quick return to baseline after events. Clear status indicators: built-in power and TTL signal LEDs on the double-panel housing make system status and alarm conditions easy to confirm at a glance. Features and functionality Outputs: DO (TTL switching output, active low) and AO (analog voltage output that varies with measured concentration). Interface: TTL output suitable for direct connection to microcontrollers and relay modules; AO suitable for ADC inputs, PLC analog inputs, or data acquisition systems. Performance: analog voltage directly reflects concentration changes; fast response and recovery for dynamic environments. Design and build: high-quality double-panel construction with separate power indicator and TTL signal output indicator for straightforward installation and monitoring. Compatibility and integration Interfacing: works with microcontrollers, relay modules, PLCs, and data acquisition systems that accept TTL digital inputs and standard analog voltage inputs. Installation: panel-style double-board design eases mounting and provides visible status LEDs for power and TTL output; wiring is simplified for embedded and industrial use. No additional conversion required for digital signaling when connecting to TTL-level inputs. Typical applications Indoor air quality and safety systems: trigger ventilation or alarms when concentration thresholds are exceeded, while logging analog concentration for trend analysis. Industrial process monitoring: provide both discrete alarms and analog feedback to control loops or recording systems for process control and compliance. Environmental sensing and research: use the analog output for precise measurement and the TTL output for event-based recording or alarm activation. What this product solves Eliminates the need for separate digital and analog interface modules by combining TTL switching and analog outputs in one sensor. Reduces integration complexity by providing a TTL active-low output that connects directly to common microcontrollers and relay modules. Improves situational awareness with fast response/recovery and visible status indicators, reducing downtime and false alarm uncertainty. Installation notes Connect TTL DO to a TTL-compatible digital input (active low). Connect AO to an appropriate ADC or analog input to read concentration-dependent voltage. Use the panel-mounted indicators to verify power and TTL output status before commissioning. This description reflects the sensor’s dual-output functionality (DO TTL and AO), TTL low-level switching compatibility with microcontrollers and relay modules, concentration-dependent analog voltage output, fast response and recovery, and the high-quality double-panel design with power and TTL signal indicators.