PT100 Flow Cell
description
Transcript of PT100 Flow Cell
PT100 Flow Cell
• Pt100 Flow Cell design
• How it works
• ELMB flow scan system
• Flow Cell calibration
• Tests for stability in gas flow measurements
EP-TA1 Gas
October 2003 Serguei Morozov
Pt100 Flow Cell designEP-TA1 Gas
October 2003 Serguei Morozov
How it worksEP-TA1 Gas
October 2003 Serguei Morozov
~ 30 sec
20°C
ELMB flow scan systemEP-TA1 Gas
October 2003
ELMB128 with theAtmega128L processor
Power supply card and Mother Card
Serguei Morozov
ELMB flow scan systemEP-TA1 Gas
October 2003
ELMB128 specification• 128 Kb of on-chip flash memory, 4 Kb of SRAM, 4 Kb of EEPROM,• Programming via CAN bus (“FLOWsCAN”, Henk Boterenbrood, NIKHEF )• 6 bipolar or unipolar input ranges (25mV - 5V)• 64-channel multiplexer
ELMB128
Twisted pair CAN
bus
Serguei Morozov
Flow Cell calibrationEP-TA1 Gas
October 2003
Calibration curve (ArCO2CF4)
First polynomial fit
Second polynomial fit
Serguei Morozov
Flow Cell calibrationEP-TA1 Gas
October 2003
-10010
2030405060
708090
2400 2900 3400 3900 4400
DataBase
Flow
Slope
Polynom coeff.
(Flow=p0+p1*x+..)
FlowSlope
DataBasefl(1)=p0+p1*x..fl(2)=p0+p1*x..fl(3)=p0+p1*x..
Serguei Morozov
Stability testsEP-TA1 Gas
October 2003
0.6 l/h6 l/h
= 10 %
1.0 l/h70 l/h
1.4 %
Tamb = 0.18 K / ADC count
Slope = 20 mK/sec
Serguei Morozov
Stability testsEP-TA1 Gas
October 2003
y = -0,0068x + 3740,3
3550
3560
3570
3580
3590
3600
3610
3620
20500 21000 21500 22000 22500 23000 23500 24000 24500 25000
Slope
Tamb 5 –7
mK/sec
K
21°C
50 l/h
28°C
55 l/h
Serguei Morozov
Stability testsEP-TA1 Gas
October 2003
The same positions in Manifold The different positions in Manifold
Serguei Morozov
Stability testsEP-TA1 Gas
October 2003
3mm 5mm
3mm: 1 mbar/cell5mm: 0.5 mbar/cell
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Pressure drop at 100 l/h :
ConclusionsEP-TA1 Gas
October 2003
• PT100 flow cell has designed (ELMB read-out, mother card)
• Parameter optimization and stability test were performed:
Time to measure 1 pair of cells (input and output): ~ 30 sec
Minimum error: ± 1 l/h
Temperature stability: + 0.7 l/h per °C ( T=20°C 24°C : 50 l/h 53 l/h)
• Gas flow ranges were estimated:
5mm flow cell: 0-30 l/h… 150 l/h and higher..
3mm flow cell: 80 l/h and higher..
Serguei Morozov