Progress report on: the Peltier-cooled frostpoint hygrometer (PCFH… · 2019-11-28 · Principle...
Transcript of Progress report on: the Peltier-cooled frostpoint hygrometer (PCFH… · 2019-11-28 · Principle...
Teresa Jorge1, Manuel Graf2, Sergey Khaykin3, Yann Poltera1
1Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland 2Swiss Federal Laboratory for Materials Science and Technology 3CNRS/INSU, LATMOS-IPSL, France
Progress report on: the Peltier-cooled frostpoint hygrometer (PCFH); and QCLAS and FLASH-B
GRUAN ICM-11 Meeting Singapore, 23.05.2019
Peltier Cooled Frostpoint Hygrometer (PCFH): Report on 2018 Activities & Status
slides adapted from
GAW-CH Landesausschuss Spring Meeting, 14 May 2019, Empa Dübendorf, Switzerland
T. Jorge1, F. G. Wienhold1, G. Cesbron1, S. Brossi2, T. Brossi2, P. Oelsner3, T. Naebert3, S. Meier3, and T. Peter1
1. Swiss Federal Institute of Tech., Zürich, Switzerland
2.mylab elektronik GmbH, Bubikon, Switzerland 3.GRUAN Lead Center, DWD Meteorological Observatory, Lindenberg, Germany
PCFH Fundamentals
Principle of Operation
Peltier-cooled mirror hygrometer instead of cryogenically-cooled like FPH or CFH (phase down agreement of the Kigali Amendment to the Montreal Protocol, 2016).
Research and test instrument: includes two independently cooled mirrors and boards.
Field Campaigns at Lindenberg
1st Field Campaign in Lindenberg, 23 .. 27 July 2018: 2 flights
2nd Field Campaign in Lindenberg, 10 .. 14 December 2018: 3 flights
Aims of the Field Campaigns No frost point measurements!
Approval of basic concepts (optical, thermal, electrical, telemetry)
Characterization of Thermal Electric Cooler (TEC) : in lab in flight environment
Characterization of condensate formation and detection (mirror reflectivity monitoring)
Gather data for instrument numerical model implementation
CFH
ECC O3 I-Met
COBALD
RS41 Twig®
RS41
OIF411
PCFH
1st Field Campaign: Flights & Payloads PCFH Flight 1 2018-0725-02UT_LI_LI236 (regular
science) 2018-0725-02UT_LI_PCFH001 Two separate RS41 telemetries
PCFH Flight 2 • 2018-0725-
20UT_LI_PCFH002: ECC O3, COBALD, CFH & PCFH
• One single RS41 CFH
ECC O3 box with OIF411
COBALD
RS41
Twig
®
spacer
PCFH
Power supply: sufficient for one flight duration
Robust: only battery replacement required after recovery.
Telemetry issues
PCFH
TEC Performance
preflight: no ventilation
ITEC (a.u.)
∆T
= T h
ot –
Tm
irror
(K
)
1st Field Campaign: Selected Results Example Profile
2018
-072
5-02
UT_
LI_P
CFH
001
sub
-uni
t 1
Frost point temperature reached only up to tropopause level. Heat load was underestimated need lighter heat sink, protection
(radiation shield) and better thermal coupling.
More space and better thermal coupling → better heat dissipation new electronics design
→ higher TEC Current achieved
1st Flights’ Version: not enough heat dissipation
PCFH Setup Revisions
CFH
ECC O3 RS41 Twig®
PCFH COBALD
RS41 Twig®
PCFH
PCFH Flight 3 & 4 (“simultaneous” launch) • 2018-1212-16UT_LI_LI246-CFH
two single stage TECs • 2018-1212-16UT_LI_LI246-COB
single & double stage TECs
All Flights telemetry problem resolved
2nd Field Campaign: Flights & Payloads
CFH
ECC O3 RS41 Twig®
PCFH
COBALD
PCFH Flight 5 • 2018-1213-
22UT_LI_LI247 single & double stage TECs
2nd Field Campaign Results: Cooling performance during ascent T h
ot ≅
Tai
r + 1
0 K
Black symbols: lab, without ventilation ∆
T =
T hot
– T
mirr
or (
K)
ITEC (A)
One assembly version achieved the wished performance.
Summary and Project Schedule Double stage TEC with increased spacing and with coupling with cupper block provides
adequate temperature range
Next steps: Improve Peltier hot side to heat sink coupling to minimize Thot – Tair (Nov-Dec 2019) → e.g. use larger cupper block
Numerical instrument model (2019- early 2020) Analyze ice formation dynamics and its effects on mirror reflectivity to introduce timing in
the numerical instrument model Add and test controller scheme in the numerical model
Field verification of the design changes Two campaigns in Lindenberg during November / December 2019 Four dual payload launches from Ny-Alesund in February 2020
Test Flights within Monitoring Networks is postponed by approximately one year (as of May 2019).
[email protected] | May 2019 |
Quantum Cascade Laser based
Absorption Spectroscopy (QCLAS)
Balloon Instrument
alides from Manuel Graf, EMPA, Switzerland
Quantum Cascade Laser based Absorption Spectroscopy (QCLAS)
[email protected] | May 2019 | 1
- Direct absorption spectroscopy
- Excitation of a rovibrational transition at 1662 cm-1 (6.01 µm)
- Open path operation (L=6 meters)
- Novel circular multipass cell allows simple & robust setup1)
Principles Mid-IR: H-O-H bending vibrations
amount fraction, ppm [μmol/mol]
QC Laser MCT Detector
multipass cell
Temperature, pressure
Method
1) Graf et al. 2018, Optics Letters
𝑃𝑃𝑟𝑟 = 𝐶𝐶 ∗ 𝑃𝑃0 ∗ exp −(𝑁𝑁𝐻𝐻2𝑂𝑂 ∗ 𝜎𝜎𝑎𝑎𝑎𝑎𝑎𝑎,𝐻𝐻2𝑂𝑂 + 𝜖𝜖) ∗ 𝐿𝐿 + 𝑃𝑃𝑎𝑎
The Instrument
gma | 13.11.2017 | 6
Specs
- On-board data storage
- Fully integrated electronics and batteries
- Thermal stabilization with phase change materials (PCM)
- 2 h autonomous operation
[email protected] | May 2019 | 2
size 30 x 20 x 10 cm3
mass 3 kg gas exchange (5 m/s ascent speed) 40 l/s power consumption 15 W measurement precision <1% measurement accuracy tba
bottom view Will be tested 2019-2020
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Alexey Lykov, Central Aerological Observatory, Russia Sergey Khaykin, CNRS/INSU, LATMOS-IPSL, France
Central Aerological Observatory, ROSHYDROMET
Fluorescence Lyman-Alpha Stratospheric Hygrometer
for Balloon (FLASH-B)
www.flash-b.ru
slides from Sergey Khaykin
The fluorescent method is based on the photodissociation of H2O molecules under UV lamp light at wavelengths below 137 nm and subsequent fluorescent relaxation of the exited OH* radical produced.
The instrument uses the open layout, where the optics is looking directly into the outside air.
Therefore, measuring only at night. For stratosphere, descent data only
Source of VUV radiation
hν
λ=121,6 nm (Lyman-α) Н2О
Н(2S)
ОН (А2∑+)
ОН (Х2П )
PMT
300 < λ < 330 nm
Н2О + hν → ОН (А2∑+) + Н(2S)
fluorescence ОН (А2∑+) → ОН (Х2П) + hν’
Method of measurement and optical layout www.flash-b.ru
Range of measurement Resolution time Integration time Precision Total uncertainty Vertical resolution Temperature range Pressure range Required power Weight (w/o batteries) Size Insulation Box Flight weight Interface to Protocol XData
0.5...1000 ppmv 1 sec 4 sec 5.5% <10 % (1σ) at µ> 3 ppmv ~ 50 m (descent in UTLS) -950C … +400C 300… 5 hPa 9-30V, 1 W max 500 gr 265 mm x 155 mm x 105 mm 1000 gr Vaisala RS92, RS41 Meisei RS-06G, Meteolabor SRS34 20 byte/sec
Specifications www.flash-b.ru
Plug-and-play concept
Flights in Dolgoprudny www.flash-b.ru
3 consecutive flights of the same FLASH sonde in Dolgoprudny with a series of calibrations before and after each flight - Consistent water vapour vertical profiles in the stratosphere and good agreement with M10 and RS41 in the free troposphere - Small change of sensitivity factor (<10 %) in between the calibrations/flights
Tropospheric comparison with RS41 and M-10
Central Aerological Observatory, ROSHYDROMET
FLASH COBALD
Application on different platforms www.flash-b.ru
The Flash hygrometer was used on board stratospheric aircraft “Geophisia” M55 during StratoClim campaign and in test flight UAV.
Thank you for your attention! Questions?
Backup slides
Thermal Electrical Cooler (TEC) Load Characteristic
double stage
single stage
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Central Aerological Observatory, ROSHYDROMET
Flight preparation www.flash-b.ru
1.Recharge battery;
2.Fixing face down;
3.Clean optics;
4.Connect to radiosonde;
5.Switch on;
6.Check the data incoming;
7.Open cap;
8.Ready to fly!
Sealant recommended against contamination in stratosphere
Plug-and-play concept
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Central Aerological Observatory, ROSHYDROMET
P: 3-1000 mBar T: 190 – 300 K µ: 1-1000 ppmv
To PC
Compressor
FLAS
H-B
Vacuum pump
dehu
mid
ifier
H2O
bu
bble
r
flow
co
ntro
ller
homogenizer
Reference dew point mirror hygrometer
MBW 373L ai
r out
flow
co
ntro
ller
Vacuum chamber
freezer
Air pressure
Calibration facility www.flash-b.ru
PCFH 2018 Activities & Status, GAW-CH Landesausschuss Spring Meeting, Dübendorf, 14 May 2019
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Central Aerological Observatory, ROSHYDROMET
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5000
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35000
132
464
797
012
9316
1619
3922
6225
8529
0832
3135
5438
7742
0045
2348
4651
6954
9258
1561
3864
6167
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6896
9110
014
1033
710
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1098
311
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1162
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1227
5
Signal MBW
Cal22 = 0.02x - 196.32
Cal25 = 0.0199x - 177.85 Cal26 = 0.0196x - 203.06
Cal29 = 0.019x - 175.82
Cal01 = 0.02x - 199.61
0
50
100
150
200
250
300
350
400
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8000 13000 18000 23000 28000 33000
MB
W[p
pmv]
Signal [counts]
Calibration data www.flash-b.ru
The total relative error of the calibration amounts to 4%.
The calibration fit function is linear in the pressure range of 30 – 150 hPa and water vapor mixing range of 1 – 500 ppmv.
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Central Aerological Observatory, ROSHYDROMET
Calculation formula www.flash-b.ru
WVMR = J*K(cal) * K(Quenching) * K(absorb.H20) * K(absorb.O2)
K(Quenching) = 1+(Q*N*(P/P0)*(T0/T)*106), where Q=2.3*10-11, P0,T0- surface pressure and temperature
K(absorb.H20) = EXP(-0.0001054*µ*P/T*L), where focus L=5 cm, P,T- pressure and temperature
K(absorb.02) = EXP(-0.0001536*P/T*L) Cal.point
If P < 36 μ = J*K(cal)*0.956*(1+0.00781*(t+273.16)/P) If 36 < P < 300 μ = J*K(cal) *(1+0.00031*P+0.00033*K(cal)2*P*J)
10th GRUAN Implementation and Coordination Meeting (ICM-10) Potsdam
Central Aerological Observatory, ROSHYDROMET
FLASH-B error budget www.flash-b.ru
Total uncertainty (calibration error + 1σ precision) is below 10% at stratospheric conditions.
Calibration error - MBW373L dew point uncertainty (0.1 K) - Pressure error (conversion to mixing ratio) - Non-linearity of calibration curve - Outgassing within calibration chamber - Random error (operator-related factors)
Total relative error of calibration is estimated at 4% (1 σ)
Measurement error - Instability of Lyman-alpha emission, including
temperature-related drifts (<3%) - Random error (5.5% precision for 4 s integration) - Detection limit 0.1 ppmv
Comparison with Pico-SDLA
Comparison with CFH Comparison with FPH In-flight repeatability
Comparison against other hygrometers and in-flight repeatability fully confirms the estimated uncertainty