# Cross-Sensitivity
#detection-technology #calibration #safety
Cross-sensitivity is the tendency of gas detectors to respond to gases other than their intended target gas, which can lead to false readings or alarms.
## Problem
When multiple gases are present, cross-sensitivity can cause:
- False positive readings
- Incorrect concentration measurements
- Misleading alarm conditions
## Examples
- Carbon monoxide (CO) detectors may react to hydrogen, ammonia, or methane
- Sensors calibrated for one gas may respond to similar gases
- Cross-sensitivity varies by sensor type and technology
## Solutions
1. **Selective Filters**: Use filters to reduce interference from non-target gases
2. **Surrogate Calibration**: Calibrate using cross-calibration factors for mixed environments
3. **Target Gas Calibration**: Always prefer calibrating with the actual target gas when possible
4. **Sensor Selection**: Choose sensors with minimal cross-sensitivity for the application
## Best Practices
- Consider all gases present in the environment during detector selection
- Account for cross-sensitivity when calibrating detectors
- Use selective detection methods when multiple gases are present
- Document cross-sensitivity characteristics for each sensor type
## Related Concepts
- [[Gas Detection Calibration]]
- [[Catalytic Bead Sensor]]
- [[Electrochemical Sensor]]