sen0469 NH3 sensor
Roberto.Fernandez 2026-06-21 01:19:41 9 Views1 Replies Hello. I have several gravity series sensors and I have problems with the data. The measurements are much higher than they should be. Supposedly they are calibrated. The board version is 1.1. What should I do to calibrate it, for example Nh3? Thank you.
Hi Roberto,
For the SEN0469/NH3 sensor, I would first confirm the warm-up time and power supply stability. Gas sensors can show very high readings if they are not fully preheated or if the environment has other interfering gases.
For calibration, use the DFRobot sample code and follow the calibration procedure from the product wiki/datasheet. Usually this involves exposing the sensor to clean air first, setting the baseline/zero point, and then using a known NH3 concentration if accurate calibration is required.
Also check:
Sensor warm-up time
Correct sensor type selected in code
Stable 5V/3.3V supply as required
Analog/reference voltage settings
Cross-sensitivity to alcohol, smoke, VOCs, or cleaning chemicals
If you're using the sensor on a custom PCB, it may also be worth verifying the analog signal routing, grounding, and power filtering. I've seen gas sensor readings affected by noise and layout issues on prototype boards. PCB design guides from PCBWay and similar manufacturers often discuss these considerations for analog sensor circuits. https://www.pcbway.com/blog/PCB_Design_Layout/Power_and_Ground_Plane_Design_Considerations_in_PCB_Layout_862aaa8c.html
If the values are still much higher after warm-up in clean air, the sensor may need recalibration or the module may be faulty.
ahsrab.rifat 