To activate the light on the ViewPoint Illuminator gently press the spot on the label marked "PRESS FOR LIGHT." Remember there are no dumb questions. If the light doesn't work, the battery may be dead. If this is the case, please send the instrument back to us and we can replace the ViewPoint.
For more information about our analog refractometers, please see the following page: How to Use a Traditional Handheld Refractometer.