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Status Graz, 24/25 Oct 2013 MUPUS Team Meeting
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2 LOWG#12, DLR Cologne 18-20th of November 2008 PEN inflight calibration 4 14 inflight calibration points between -107°C and -91°C 3 PEN sensors (No 2,7,10) showed jump (< 0.5 K) in R-T characteristic after THC power calibration in PC#12 No changes between PC#12 and PC#13 => correction possible No active heating before FSS !
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3 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS PEN Inflight Calibration 5 R0(-100°C) and TCR(-100°C) from 16 inflight calibration points between -107°C and -91°C Corresponds to TCR ~ 0.0022 when evaluated with standard T0=0°C
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4 LOWG#12, DLR Cologne 18-20th of November 2008 (prelimenary) PEN uncertainty budget Uncertainty(@T=-200°C, k=2) = 3.2 K uncertainties of reference resistors R100, R20 uncertainty of h/k-2 Pt-100 (Class B, incl. line resistance correction ~ 1K / 3 1/2 ) Precision(@T=-200°C, k=2) = 2.6 K Uncertainty due to linear extrapolation Uncertainty due to neglection of quadratic term (2-3 10 -7 K -2, FS measurement) Uncertainty due to imperfect wire correction (assumed 20% of nominal R w ) Uncertainty due to assumption of homogeneous PEN temperature (assumed 0.5 K / 3 1/2 ) Uncertainty due to electronics nonlinearity (FS, 0.25 K / 3 1/2 ) Uncertainty due to electronics noise (0.016 K, FM cruise checkouts) 1-Sigma
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5 LOWG#12, DLR Cologne 18-20th of November 2008 TM inflight calibration 2 6-25 µ 13-15 µ TM sensors lost sensitivity (but stable during cruise)!
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6 LOWG#12, DLR Cologne 18-20th of November 2008 TM inflight calibration 4 6-25 µm13-15 µm Extrapolation to TV test conditions: S/S 0 ~ 0.72 (6-25 µm) S/S 0 ~ 0.86 (13-15 µm)
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7 LOWG#12, DLR Cologne 18-20th of November 2008 Depth Sensor FM FS DS values stable since 2006 (no data earlier) Slight dependence on balcony temperature (similar for FS) Precision (Repeatibility, FS) ~ 75 DU (~ 3.5 mm)
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8 LOWG#12, DLR Cologne 18-20th of November 2008 ANC-M (accelerometer) FM FS ANC-M Offsets stable since PC#4 (Nov 2006) Slight dependence on board (EBox) temperature ~ -1 mV/K Noise stable at 0.6-0.7 mV
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9 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS FM Status Summary All MUPUS hardware fully operational when entering hibernation ComDPU working only at ½ nominal speed (known since 2006) No indications for h/w changes during cruise with one exception: 3 PENEL sensors showed jump in R 0 (~0.5-1 K) after (very low power) THC heating Calibration problems exist: PENEL: extrapolation due to short baseline of inflight calibration points TM: significant sensitivity loss already pre-launch
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10 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS RM Status EQM DPU killed in Nov 2012 Stupid handling error by the project manager ! Replaced by last FM-series (reserve) DPU stored at DLR RM functional BUT: new PENEL-FS problem Occured after insertion tests with SESAME at Philae GRM Strange: everything ok during all functional tests including the last one before switch-off No valid measurements anymore when red tag jointer connecting PENEL electrical to structural GND close Everything ok when red tag jointer open !
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11 LOWG#12, DLR Cologne 18-20th of November 2008 Additional slides
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12 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS PEN Inflight Calibration 1 Inflight calibration needed to cover low T expected for the comet Method: Use Pt-100 in the holder as reference Assume that PEN tube and holder at the same temperature in equilibrium (before PENEL switched on, justified by TV test with PEN FS) Interpolate resistance backward in time to start of PENEL preheating (equilibrium) => R i =R i (T ref ), i=1,2,…,16 PEN1 PEN16 TCU-MUPUS-DD Pt-100 PENEL, T=-50°C
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13 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS PEN Inflight Calibration 3 Backward Extrapolation Calibration (holder) Pt-100 Nearly linear increase of R during first 30 min. Backward extrapolation gives reasonable R(T) point ! (random) uncertainty estimate ~ 0.5 K (neglecting deviations from homogeneity assumption) + systematic uncertainty of T holder ~ 0.8 K PENEL heat wave
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14 LOWG#12, DLR Cologne 18-20th of November 2008 MUPUS TM Calibration 1 Thermopile principle: T-differences between sensor and object => U th T Sens must be measured separately ! Object radiation Housing radiation Blackbody radiation
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