General Eastern C-1 RH Generator Questions

[Hawaii596]

If anyone has substantial experience using the General Eastern C-1 RH Generator (with General Eastern HYGRO M2 / 1111H-SR Chilled Mirror), this is for you.

The rated specification is 0 to 95%RH for the C-1. The 'new' replacement model C1M (which looks like it is the same instrument) is specified from 10 to 95%RH.

I am wondering if anyone who has used this system substantially has ever been able to set it for 0%RH and actually reach that setpoint. I have been experimenting, including the addition of dry Nitrogen at the input of the C-1 (at OEM recommended flow rate of 8 SCFH). I have the test chamber properly sealed, with the prescribed very slight leak at the edges to maintain neutral barometric pressure.

I want to know if this system was over spec'd and just can't reach 0%RH, or if a well working system will actually reach that set point. The fact that they changed the operating range on the new version makes me wonder if the original model was overspec'd and could never actually reach 0%RH. Or are there system maintenance things I need to do to get my C-1 to reach full specs.

[OlDave]

Just a thought....Are you using the standard short little teflon tube from the chamber to the chilled mirror? It has been my experience that tubing like that is semi-permeable to water vapor. I had much better luck with very low dew points if I switched to copper tubing.

[GA_PMEL_RF]

We got a GE chilled mirror system and GE says to use SS tubing to prevent RH leakage.  ALso to have exit tubing of at least 4ft to 6 Ft.   Copper Tubing may be subject to corrosion.
R. Francis