Instructions for Mel-8704R-SDD

The Mel-8704R-SDD works with:

* A RED or GREEN Laser Grid
* A RED or GREEN Laser Pointer
* LED Flashlight 

* The Mel Meter Flashlight can also be used as a diffuse reflective sensor up to 5′ away. This feature enables detection of reflective or solid objects that pass in front of the Mel Meter. Or, turn the Mel
flashlight OFF to detect self illuminating or glowing objects in the field of view. 

* You can use the light from a RED exit sign, street light coming through a window, or any other indirect  “stable” incandescent light.


1. Turn on the Mel-SDD circuit located behind the Mel Meter Tilt stand.  The SDD circuit will beep twice and   then default to the least sensitive detection range, sensitivity level #1. There are a total of 5 sensitivity levels.

2. On the side of the Mel Meter is a momentary push button labeled “SDD Sensitivity”.   Press this Button twice. You will hear a Beep each time the button is pressed. Pressing it twice will  increment the SDD to sensitivity level #3 based on the initial Power Up default starting at level #1.

3. Position the Mel Meter on a tripod or flat surface so that the light intensity sensor located above the  Mel flashlight is aimed in the general direction of the RED LED illuminator. The RED LED
illumination source can be located up to 75′ away. It is not imperative to have the illumination source perfectly aligned with the light intensity sensor because the SDD has an automatic 5 sec. light calibration feature.

4. Test the detection sensitivity by slowly moving the RED LED illumination beam to the left or right side of the SDD  detector so that only minimal light is received. The SDD will produce a four step descending tone pattern. Then,  move the illumination so that the SDD receives more light and you will hear an ascending tone pattern.

Important Note: The SDD performs a diagnostic test and recalibration every 5 seconds. So, if the
processor diagnostic & calibration routine falls within the time of your test, it could momentarily reverse the tone pitch. This will be automatically corrected during the next 5 sec. cycle.

5. Once you get a good feel for the way it operates, you can try different techniques. To use the Mel-SDD as a diffuse  reflective sensor, adjust the sensitivity to Level # 4-5. Then turn on the Mel Meter RED flashlight. Allow the detection circuit to stabilize with nothing in front of the Mel Meter. Now move your hand in front of the Mel  Meter through the flashlight beam. The SDD will detect your hand up to a 4′ distance.  Be sure that you are in complete darkness when you do this.  To detect a self illuminating source, turn the Mel flashlight OFF. Strike a match, use a lighter or turn on a  flashlight within the Mel-SDD field of view.

As always, adjust the sensitivity for best performance based on type of light source, proximity or
separation distance and individual application circumstances. If you lose track of which sensitivity setting  you have, simply turn the SDD OFF then ON to reset back to sensitivity level #1.  Also be aware that stray light from windows, cars, moonlight, flashlights etc. can all influence the SDD.