Clean and inspect the fiber connectors, as dirt or damage can lead to power loss, and ensure the fiber isn't bent or twisted. If your laser power meter shows a negative reading, check the following: In most cases, correcting the measurement conditions resolves the issue immediately. In this video, we explain how to repair an Optical Power Meter that powers ON but does NOT show any optical power reading. But in many cases, the issue is not the laser, and not necessarily the sensor. What may be happening is a thermal effect inside the sensor: when the sensor body is warmer than the absorber. A power meter is only as accurate as the technician using it.
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