design and construction of the gallium melting point
DESCRIPTION
Design And Construction Of The Gallium Melting Point. Jovan Bojkovski, Miha Hiti, Valentin Batagelj EUROMET 732 project, WP 5 MIRS/FE-LMK 24.11.2006. Summary. Activities so far Design Material Cleaning process Filling process Testing Future activities Analysis of the material - PowerPoint PPT PresentationTRANSCRIPT
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Design And Construction Of The Gallium Melting
PointJovan Bojkovski, Miha Hiti, Valentin
BatageljEUROMET 732 project, WP 5
MIRS/FE-LMK24.11.2006
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Summary
• Activities so far– Design– Material– Cleaning process– Filling process– Testing
• Future activities– Analysis of the material– Analysis of the design and its influences– Intercomparison with other laboratories
(SMU, ...)
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Design (1)
• “Classical” design (YSI, Isotech, ...)• So-called virgin teflon as basis for
enclosure and thermometer well• Only two parts decrease of possible
leakage• Inside and outside aluminium tube in order
to increse radial heat transfer• Dimmensions same as commercial
possibility to realize it inside special furnace
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Design (2)
•30 cm length•3,5 cm width•Thickness of the walls 2 mm•Immersion depth 20 cm
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Material (1)
• Nominally > 7 N purity• Source of material China (Guangzhou
Youyuan Metals & Chemicals Co.,Ltd.)• Very cheap material risk of getting
material of poor quality– 1 kg of Ga = 700 $– 1 kg of Zn = 780 $
• However, we didn’t have any experience high possibility of errors and contamintion of better and more expensive gallium
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Material (2)
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Cleaning process (1)
• Dry cleaning to eliminate any leftovers from machining process
• Cleaning with mild detergent• Cleaning with pure alcohol• Cleaning with double destilled water• Ultrasonic cleaning with destilled
water
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Cleaning process (2)
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Filling process (1)
• It has been filled inside dry-box• Known concentration of water vapour
(< 20 ppm) and oxygen (<1 ppm) inside the dry-box
• Material melted and filled to the teflon container and closed inside controlled atmosphere
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Filling process (2)
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Testing
• Only part of testing has been made• First stage is direct comparison to
the reference cell used in EUROMEt 552.K3
• Realization inside different thermal enclousers
• Difference from reference cell is +40 microK
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
28,57892
28,57897
28,57902
28,57907
28,57912
28,57917
28,57922
17.12.200310:00
17.12.200312:00
17.12.200314:00
17.12.200316:00
17.12.200318:00
17.12.200320:00
17.12.200322:00
18.12.20030:00
18.12.20032:00
18.12.20034:00
date and time
resi
stan
ce
in o
hm
s
0,5 mK
Reference cell
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Stability of resistor bath
22,998
22,999
23
23,001
23,002
23,003
23,004
23,005
13.1.200412:36
13.1.200415:00
13.1.200417:24
13.1.200419:48
13.1.200422:12
14.1.20040:36
14.1.20043:00
14.1.20045:24
14.1.20047:48
14.1.200410:12
14.1.200412:36
date and time
tem
per
atu
re in
°C
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
New cell results (1)
28,417
28,41705
28,4171
28,41715
28,4172
28,41725
28,4173
28,41735
28,4174
18.10.2006 15:27 18.10.2006 20:15 19.10.2006 1:03 19.10.2006 5:51 19.10.2006 10:39 19.10.2006 15:27
date and time
resi
stan
ce
in o
hm
s
0,5 mK
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
New cell results (2)
28,4171
28,41712
28,41714
28,41716
28,41718
28,4172
28,41722
28,41724
28,41726
28,41728
28,4173
18.10.200615:46
18.10.200615:48
18.10.200615:51
18.10.200615:54
18.10.200615:57
18.10.200616:00
18.10.200616:03
18.10.200616:06
18.10.200616:09
18.10.200616:11
date and time
resi
stan
ce
in o
hm
s
0,2 mK
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
New cell results (3)
0
0,00002
0,00004
0,00006
0,00008
0,0001
0,00012
0 1 2 3 4 5 6 7 8 9
distance from the bottom in cm
tem
pe
ratu
re d
iffe
ren
ce
in K
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Problems
• Long response time– Thickness of teflon ?
• Repeatable decrese at the beginning of the plateau– Material composition
• “Short-circuit” of the material thermometer is influenced by the furnace
• ......
Laboratory of Metrology and QualityFaculty of Electrical EngineeringUniversity of Ljubljana
MIRS/FE-LMK
Further activities
• Analysis of the material• Analysis of the design and its
influences• Intercomparison with other
laboratories (SMU, ...)• Building new cells from existing
material• Buying new material if necessary