Plasma startup

[nkhanbham]

Hello fellow users.
We are new Helios users and are having some problems as expected. We have been getting a whiny/whistling sound during plasma startup that begins shortly after ignition. Has anyone else experienced this? I am told this is due incorrect alignment / fitting of the torch assembly. Any feedback would be most welcome.
Many thanks.
Naeem

[mleipold]

Hi Naeem,

I'm not sure that I understand what you're saying: you start up the machine, you get the hissing sound of the gate opening and closing, you get the interface pump kicking on, about 30 second later you hear the "pop" of plasma ignition, and *only then* do you hear the whistling sound? Has the gate light switched back to "OPEN" by the time you hear the whistling sound?


Mike

[Chowduck]

Hi Naeem,

Sounds like you do not have a good seal between the torch assembly and the housing of the instrument. I suggest you unscrew and remove the torch assembly then look at the plastic hose clamp that is holding the clear gas line onto the torch assembly. If the hose clamp is loose it can rotate on its own so the part you squeeze is radially out. If this is the case it will prevent the torch assembly from making contact with the housing. When you power up the plasma air will rush past this opening and cause a whistling/gas leak noise.

I’ll see if I can take a few pictures that will show what I’m describing.

-Greg

[nkhanbham]

Mike and Greg,
Thanks for the replies. Yes the sound is shortly after plasma ignition but no the gate light doesn't revert to open. I aborted the startup as I was worried that this may cause some damage to the instrument/components. Anyway I took the torch assembly apart then reassembled. It is now firing up normally without the loud whistling.
Bw,
Naeem