An emergency Flow tube can be a properly sized chunk of Pyrex or Fused Silica tubing. Professional flow tubes block UV, some IR, and spectral shift some of the undesired light to something useful. So you loose 3-5% of your overall output power, if you do not use a professional flow tube. No flow tube = cracked lamp seals, so do please install something. The ends on Pyrex flow tubes should be flame polished and if possible the tube should be annealed. Pyrex is preferred in this case as it adsorbs UV.
If LSOS or Kentek can help you, then the flow tube may not be so expensive.
Steve
Last edited by mixedgas; 10-17-2013 at 17:34.
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