<GIFTS_T_Uncert&Cal.ppt>9 March 2004

GIFTSBlackbody SubsystemCritical Design Review

Temperature Uncertainty Budget and Calibration

Fred Best

9 March 2004

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 2

Temperature Error BudgetTemperature Uncertainty 3 sigma error [K] RSS [K]

Temperature Calibration Standard* 0.005(Thermometrics SP60 Probe with Hart Scientific 2560 Thermistor Module)

0.005

Readout Electronics Uncertainty (at delivery)* 0.0140.014

Blackbody Thermistor Temperature Transfer UncertaintyGradient Between Temperature Standard and Cavity Thermistors** 0.020Calibration Fitting Equation Residual Error** 0.005

0.021

Cavity Temperature Uniformity UncertaintyCavity to Thermistor Gradient Uncertainty (1/3 of total max expected gradient) 0.030Thermistor Wire Heat Leak Temperature Bias Uncertainty* 0.008Paint Gradient (assumes nominal HBB Temp and conservative viewing geometry) 0.018

0.036

Long-term StabilityBlackbody Thermistor (10 years of drift assuming 105 C) 0.050Blackbody Controller Readout Electronics* 0.012

0.051

Effective Radiometric Temperature Weighting Factor UncertaintyMonte Carlo Ray Trace Model Uncertainty in Determining Teff 0.030(1/3 of total max expected gradient) 0.030

*Presented in earlier section 0.074**Based on experience with UW AERI Blackbodies

Blackbody Readout Electronics Uncertainty

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 3

Blackbody Section – Side View

Enclosure Tube(Aluminum)

FrontCover(Alum)

Multi-layer Insulation(not shown)

Cavity Support/Insulator (Noryl)

ElectricalConnector

MountingBase (Noryl)

Circumferental Heater

Thermistors 4 Temperature Measurement 2 Redundant Temp Control 1 Overtemp

Blackbody Cavity(Aluminum)

ChemglazeZ306 Paint

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 4

Blackbody Temperature Calibration Configuration

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 5

GIFTS BB Calibration Scheme

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 6

Blackbody Temperature Calibration

• The Blackbody and Controller will undergo end-to-end calibration.

• The temperature of the Blackbody and Controller can be independently controlled.

• Ambient Blackbody calibrated over the range from: -40 C to 0 C.

• Hot Blackbody calibrated over the range from: 0 C to +40 C.

• For calibration the Controller will be maintained at near 0 C. {The system will be calibrated at other Controller temperatures if a temperature dependence is discovered during EM-2 testing.

<GIFTS_T_Uncert&Cal.ppt>9 March 2004

Slide 7

Temperature Calibration Standard

AbsoluteTemperatureCalibration of end-to-end System at Hart has UncertaintyOf +/- 0.003 K (k=2)

ThermometricsSP-60 Probes (2)

• Hart 2563 Standard Thermistor Module• Hart 2564 Thermistor Scanner Module• Hart 3560 Extended Communications Module• Calibration Computer