5
(6). Measurement
To assure accurate measurements, tighten the connectors securely,
maintain the physical configuration of the fiber during measurement,
and do not allow ambient light to enter the sensor. If optical power
input falls outside of the measurement range during operation,
range indicators will appear in the display as: over (Hi-dBm) and
under (Lo-dBm).
(7). Relative measurement
To set the current input power as the reference level, hold down the
“(REL)” button for more than one second. The difference between
the reference level and subsequent power input is expressed in dB.
These measurements are called “relative values” and can be read
directly, requiring no manual calculations.
In this mode, "REL" appears in the display.
If the “(REL)” button is pressed again, the unit will return to dBm
mode.
(8). Automatic offset compensation
This function effects automatic offset compensation of the optical
input port, canceling out any offset value, which may cause large
errors when measuring extremely low light levels.
To perform this function, completely blind the input port with the
protection cap and turn on the power while pressing the “ (REL)”
button.
The countdown will be displayed. It will be complete in about 10
seconds.
To cancel this function, press “(REL)” button again during the
countdown, and then the unit will be in dBm mode without the offset
compensation.
If the blind of the input port is not enough so that the compensation
cannot be accomplished, “Err”will appear in the display. In this case,
press “(REL)” button again, and then the unit will be in dBm mode
without the offset compensation.
3-3 Battery replacement
If the “B” mark appears in the display, replace the battery to new
one.
