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Re: Humidity calibration
Dear Peter,
exist big differences between calibration and using the "generator of
the known humidity". Now we have working version that we will use
liquid nitrogen for callibration. In this case I have to calculate
"time of refilling". For calibration during 2-3 days I can refill each
4 - 5 hours and I do not need in the level control. In case of
"generator humidity" during the experimen this system has to have
another "stability level". Deside, please, what do you want...
With best regards Sasha.
On 4/27/06, Peter Kammel <kammel@npl.uiuc.edu> wrote:
> Dear Sacha,
>
> I believe that's a good plan, we can all agree about. We had money
> in CRDF for upgrade of the CHUPS system. I am sure we could use it
> for this project.
>
> You call your project a calibration of the humidity sensor. We could
> turn the argument around. If you can proof that this method
> provides a high precision humidity generator, we can directly
> use it during next run for generating our TPC input flux. Then
> we would even be independent of potential stability issues
> of the HS.
>
> Best regards
>
> Peter
>
> On Thu, 27 Apr 2006, Alexander Vasilyev wrote:
>
> > Dear Colleagues,
>
>
>
> before proposal about humidity sensor calibration I assumed that separator
> will finish its job this year. If not, we CAN NOT disassemble separator - no
> questions!
>
>
>
> In this case the most easy way for calibration is to use as a source of cold
> liquid nitrogen. The temperature is suitable. All instabilities will be
> corrected by the Xe pressure stabilization.
>
>
>
> So, I can start production of the independent system for the calibration. I
> hope I can use current CRDF for it (if collaboration agrees).
>
>
>
> 1. Vacuum chamber with liquid nitrogen volume, Cu heat bridge, Xe volume,
> H2 heatexchanger.
>
> about 1000 Eur manpower and 700 Eur materials.
>
> 2. 1 cryogenic Pt 100 - Claude has it.
>
> 3. 1 pressure sensor for Xe. We can not use pressure sensor from H2 lines.
> It means we have to buy it.
>
>
>
> http://www.keller-druck.com/picts/pdf/engl/33xe.pdf
>
>
>
> If we can buy PPA 33X for 10 bar with RS485 and "extra precision" we can
> make unic measurements with absolute calibration of humidity sensor on the
> level +/-3% at 20-30 ppb.
>
> Could I ask you to get offer from Keller?
>
> 4. We will not use differential pressure sensor form the separator. Exist
> another methods to control the system.
>
> 5. Electronics from separator will control the humidity calibrator. Nothing
> new exept software (Peter's job) and cabling.
>
> 6. Job with humidity calibration will take 2 weeks of 3 persons (I, Marat
> and Peter).
>
>
>
> This job can be done in Gatchina before the end of September and in October
> in PSI.
>
>
>
> I really think that we have to do it! This method will be MORE precise then
> in the firm which produced humidity sensor. The reason is very simple, we
> have to calibrate in a VERY narrow range at OUR conditions (10 bar of
> hydrogen) with OUR electronics. Real conditions and electronics can produce
> additional errors.
>
>
>
> With best regards Sasha.
>
>
>
>
>
>
>
> .
>
>
> Peter Kammel / pkammel@uiuc.edu
> Department of Physics, Loomis Laboratory
> University of Illinois at Urbana-Champaign
> 1110 West Green Street, Urbana, IL 61801
> Tel (217) 333-5424 / Fax (217) 333-1215
>
>
>
--
Vasilyev Alexander
Petersburg Nuclear Physics Institute,
Laboratory of Cryogenic and Superconductive Technique.