Module No. 3513

Viewing the Face in the Dark

The face of the watch can be illuminated for viewing in the dark.

To illuminate the face manually

Pressing (L) turns on illumination.

Illumination will turn off automatically if an alarm starts to sound.

Illumination may not turn on while a sensor is taking a reading.


To illuminate the face when Auto Light is enabled

If Auto Light is enabled, face illumination will turn on automatically whenever the watch is positioned at an angle of 40 degrees or more.



Auto Light may not operate properly when the watch is at a horizontal angle of 15 degrees or greater from horizontal as shown in the illustration below.


Electro-static charge or magnetism can interfere with proper auto light operation. If this happens, try lowering your arm and then angle it towards your face again.

When moving the watch you may note a slight rattling sound. This is due to operation of the auto light switch, which determines the current orientation of the watch. It does not indicate malfunction.


Auto Light is disabled when any one of the conditions below exists.

Alarm, timer alert, or other beeper sounding

Watch in the Compass Mode

While sunrise/sunset times are being calculated

Configuring the Auto Light Setting

  1. Enter the Timekeeping Mode.

  2. Hold down (L) for at least three seconds to toggle Auto Light between enabled and disabled.

  3. [LT] is displayed while Auto Light is enabled.



Auto Light is disabled while [CHG] is shown on the display.

Specifying the Illumination Duration

You can select either 1.5 seconds or three seconds as the illumination duration.

  1. Enter the Timekeeping Mode.

  2. Hold down (E) for at least two seconds. Release the button when the name of the currently selected Home City appears on the display.

  3. 3513_fl_SET_HT_comon
  4. Press (D) 10 times.

  5. [LIGHT] appears on the display with [1] or [3] flashing.

  6. Press (A) to select an illumination duration.

  7. [1]: 1.5-second illumination

    [3]: 3-second illumination

  8. Press (E) twice to complete the setting operation.