PEARL - Warning Sensors are Blocked!

SMS Smart App / T.M.A.S. Alerts

Table of Contents


    This article will help you resolve blockage issues with your Pearl unit(s).

    To count, the Pearl units, through their two small holes ("eyes") at the bottom, "throws" infrared signals to each other. The Pearl uses a set of double Infrared Beams, and when the Main units does not detect the beams of the secondary for more than 60 seconds, the Pearl reports it, and if the situation continues in the next few minutes, an alert is generated. 

    There are various situations to look for to resolve a blockage issue. Let's start:

    Quick overview on blockage

    Possible Object causing blockage

    The 2 holes, of the 2 PEARL units, need to be "looking" at each other. Anything that stops this from occurring will block the infrared beam. Here are some examples of common objects that ends up between the two PEARL units, which would need to be moved away.

    • Signage may be obstructing the beam
    • Plants, Furniture, or displays may be obstructing the beam
    • A new store design or shelving may now be obstructing the beam
    • A customer staying between the units


    Review Batteries

    Make sure that you've changed the batteries in the Secondary unit at the same time as the Main unit. 
    Also, make sure that you use our recommended batteries, cheaper batteries are known to not power the Pearl unit properly and cause issues!

    Possible battery issue causing blockage

    Depleted batteries or very low batteries on the Secondary unit.

    If the Secondary unit's batteries are depleted, then the Main unit will report a blockage as it no longer "sees" the beam of the secondary unit. Replacing the batteries will resolve this situation.

    Blockages due to an installation error

    Here are a few installation errors that will trigger blockage alerts. The first step will be to make sure the PEARLs are properly installed and that the two holes (their "eyes") of each unit are pointing to each other. 

    PEARLs not properly aligned

    • Incorrect installation, Pearl Main and Secondary not aligned properly

    PEARLs not facing each other

      • Incorrect installation example of a PEARL facing towards the outside of the store
      • Correct installation example of a PEARL facing each other

    PEARLs partially blocked: Door frame

    • Incorrect: in the following picture (identified in red) the door frame is partially blocking the PEARLs beam.
    • Correct: in the following picture (identified in green) the PEARL has been relocated on top of the door frame. 

    Doors on pivots

    If your doors are on a type of pivot vs standard door hinges, make sure that when the door opens that it not blocking one of the beams. This is a limitation as the below Pearl is partially obsctructed causing blockages. 

    Vertical Door handle blocking the PEARLs

    • In the following picture (identified in red) the PEARL is partially blocked by the door handle.

    To resolve either you'll have to find another mounting location or create a spacer to clear the door handles.

    Third-Party Infrared Interference

    If there are no visible issues and if you are receiving intermittent PEARL blockages alert, there might be infrared interferences from another device.

    1. Ensure there are no older infrared beam people counting sensors at the entrance. If this is the case, remove them.

    2. If you have Anti-Theft pedestal, ensure they do not have an optional infrared beam traffic counter installed and activated, as those will interfere with the PEARLs.

    3. Should you have a fully automatic door, you most likely have an infrared safety sensor. Take a look at our special installation guide regarding automated doors with infrared safety sensor. Reference article: Automated door installation

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