Where is the Electron Multiplier horn in an MS 6120?


From a previous question (link) I was told to change the electron multiplier horn.

In the manual there are pictures of the EM, however, there is no path on how to get there.

I am attaching a picture of my 6120 where I removed several panels. Can anyone guide me to find the EM?

Thank you

  • Hi Danielchsny,

    You first need to make sure the system is vented. Then you will need to remove the electronics box above the desolvation chamber. To do that, you will need to unplug the Vcap/Vchamper power supply (white plug seen at the bottom of the middle top picture you posted), ensure that the T20 captive screw above the desolvation chamber is loose, and then lift up the electronics box. Once you have removed the electronics box from the top, you can remove the metal plate that sits on top of the detector manifold. The electron multiplier is at the back of the manifold behind the quad.

    Good luck!

  • Hi Brad

    Thank you for your instructions.

    Here is my progress in digging...

    I remove front panel, very carefully, disconnecting the gray multicable

    Then disconnected 2 white connectors: one frontal side, the second in my left side of the metallic box:

    I unscrewed the  holding screw, which does not come out, but allow to raise the metalic box. Problem, there are 3 more conectors on the side:

    I could take out the 'main board' one. The other two I could not. However, I could carefully move the box to one side.

    Under the metallic bos there is a glass or metal cover super shiny.

    I took it out...

    Found it!

    I am going to read how to replace the EMhorn and report here.  Any input will be appreciated!


  • Reading the manual, and it is a little bit confusing:

    Can anyone indentify in the image I put:

    -electron multiplier

    -electron multiplier horn


    -vacuum manifold

    -high energy dynode


    So far I think:

    Red- Electron multiplier

    Orange - EM horn

    Green - Resistor

  • This orange one is called Electron multiplier horn and need to replace when it reached to it's maximum volt..It is fastened with two clip and connected with wire as u can see in ur picture..

  • Thanks,

    The colored parts were already identified (see the previous post) and Andy helped with the Voltage (link)

    What are still missing:

    -vacuum manifold

    -high energy dynode

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