# LI-190R & LI-191R Help Center
- [LI-190R & LI-191R Help Center](home.md): Product support landing page.
## Instruction Manual
- [Instruction Manual](manuals.md)
- [1. General Information](topics/quantum-general-information.md)
- [2. Using the Quantum Sensors](topics/quantum-using.md)
- [3. Millivolt Adapters](topics/quantum-mv-adaptors.md)
- [4. 2420 Light Sensor Amplifier](topics/quantum-2420-amplifier.md)
- [5. Performance Characteristics](topics/quantum-performance.md)
- [6. Care and Maintenance](topics/quantum-maintenance.md)
- [7. Troubleshooting](topics/quantum-troubleshooting.md)
- [A. Specifications](topics/quantum-specifications.md)
## Documents
- [Documents](docs.md)
- [Amplifying the Output Signal of Radiation Sensors](Light-Sensors/topics/ttp003-amplifier.md)
- [Light Sensor Amplifier 2420](Light-Sensors/topics/2420-quick-start.md)
- [Converting Light Sensor Output to Voltage](Light-Sensors/topics/ttp004-voltage-reader.md)
- [Wireless Light Sensor Network with Particle Argon](Light-Sensors/topics/wireless-light-sensors-particle-argon-platform.md)
- [Wireless Light Sensor Network with NI](Light-Sensors/topics/wireless-sensor-networks-national-instruments.md)
- [Calculating the Calibration Multiplier](topics/faq001.md)
- [Comparison of Quantum Sensors with Different Spectral Sensitivities](topics/quantum-comparison.md)
- [How to Prevent Negative Readings](Light-Sensors/topics/negative-readings.md)
## Videos
- [Videos](Light-Sensors/videos.md)
- [Using Light Sensors with the LI-1500](LI-1500/videos/connect-to-li-1500.md)
## FAQs
- [FAQs](faqs.md)
## Factory Calibration
- [Factory Calibration](factory-calibration.md)