1The fiber optical power meter has 3 kinds of connector and can measuring 7 kinds of wavelength. 2Resistant to shock and wear,very strong and durable. 3The measuring is of high accuracy and the response is quick. 4Can working normally at temperature -10~ 60. 5Powered by 3 pcs AA battery,each to switch battery.Item Type:Fiber Optical Power Meter_x000D_Wavelength Range: 800-1700_x000D_Connection Port: SC/FC/ST_x000D_Probe Range: IngaAs_x000D_Measuring Range: -70~ 3db_x000D_Uncertainty: 5%_x000D_Linear Display: 0.1%_x000D_Working Temperature: -10~60_x000D_Storage Temperature: -25~70_x000D_Automatic Shutdown Time: 10min_x000D_Battery:3 x AA Battery(Not Included)1 x Power Meter1 x ConnectorThe LED display is weak and the boot cannot be displayed._x000D_It may be because the battery is low, you can replace the battery in time._x000D__x000D__x000D_LED display data is not normal?_x000D_It is possible that the connector is faulty, dirty or locked. Reconnect the connector and clean the sensor_x000D__x000D__x000D_How to restore the factory settings?_x000D_Press the "in" "zero" button at the same time_x000D__x000D__x000D_The calibration steps are as follows:_x000D_1. Press the "" "LIGHT" button at the same time, the "nm" at the end of the first line is not displayed._x000D_2. Each time the LIGHT button is pressed, the power value is increased by 0.05dBm, and the power value is adjusted to the standard value by these two buttons._x000D_3. Press the "zero" button to save_x000D_4. Restart the optical power meter or press the "in" "LIGHT"_x000D_The "nm" at the end of the first line of the key is displayed and ready for use.