Turn off the power to the light source and the optical power meter

To remove or disable the light source on an optical power meter, you can either disconnect the external source or turn off the meter's internal LED using the dedicated control key.Disconnecting an External Light SourceIf your optical power meter is connected to an external light source, simply disconnect the fiber at the meter input. Ensure the meter is powered on and zeroed (or referenced) before disconnecting to avoid invalid readings. The meter will then measure only ambient light or no light, depending on the environment ( ).Turning Off the Internal LEDMany optical power meters, such as FS models, include a built-in LED for testing or alignment. To disable this internal light source:Press the LED key to toggle the flashlight on or off ( ).For meters with combined functions, pressing LED + REF/dB keys simultaneously may enter calibration mode, but the LED can still be turned off independently ( ).Zeroing the MeterAfter removing the light source, it is recommended to zero the meter to ensure it reads 0 dBm or 0 W when no light is present. This is typically done by covering the sensor and pressing the zero or null button ( ).Safety and Accuracy TipsAlways handle connectors carefully to avoid contamination, which can affect readings even when the light source is removed ( ).Do not attempt to physically remove internal components unless authorized, as this can damage the meter.Use the protective cap on the optical input when the source is disconnected to prevent dust or debris from entering ( ). By following these steps, you can safely remove or disable the light source from your optical power meter while maintaining accurate measurements.