21 11 2006
Pisa University

Peek coil under vacuum with a constant voltage applied to its terminals

Platinum element S249PD
	R0 100Ohm @ 0 degree celsius +- 0.12%
	alpha 0.00385
	probe placed on the coil support and wires
	wound on top of it
	Calibration T = (R-100)/0.385;
Coil 
	Resistance 514Ohm
	Layers 		8
	turns 		1000
	Outer Diamater 90mm
	Wire diameter 130um
	Material : Peek

 rho copper 0.016 Ohm m / mm^2 ??


----------------------------------------------------
First Test

Coil under vacuum at room temperature  with 15V on its leads
Measuring PT resistance, Current and Time
Supplying Voltage 15V	



Fit Temperature vs time
	File
		Name: Coil.15V.TempCurrentVSTime.out
		Columns: #Current(mA)	PT100 Resistance(Ohms)	time(minutes)

	Pressure 
		Begin 0.045mbar
		End   0.035mbar

	Fitting Function: y(x)=a*exp(b*x)+c

	Parameters:
                        a = -1.03532e+01 +-  2.03800e+00
                        b = -1.09661e-01 +-  2.38900e-02
                        c =  3.45216e+01 +-  2.44300e-01

	Degrees of Freedom = 8

	Reduced ChiSquare = 1

	Correlation Matrix:
                        a  1.00
                        b  0.87  1.00
                        c  0.27  0.58  1.00

	 Coil.15V.TempVSTime.fit.pdf
	
	Time constant : ~9 minutes


Fit Current vs time

	Fitting Function: y(x)=a*exp(b*x)+c

	Parameters:
                        a =  7.80223e-01 +-  1.40300e-01
                        b = -6.42833e-02 +-  2.11900e-02
                        c =  2.87891e+01 +-  4.86600e-02

	Degrees of Freedom = 9

	Reduced ChiSquare = 1.00048

	Correlation Matrix:
                        a  1.00
                        b -0.67  1.00
                        c  0.03 -0.65  1.00

	Time constant : 15.5 minutes

	Coil.15V.CurrentVSTime.fit.pdf 

----------------------------------------------------
Second Test

Coil under vacuum at about 35C with 30V on its leads
Measuring PT resistance and Time
Resistance read using a HP3441A Multimeter

	Pressure 
		Begin 0.035mbar
		End   0.030mbar


	File
		Name: Coil.30V.TempVSTime.out
		Columns: Resistance (Omhs), Time(Minutes), Time(seconds)
 
	Current after 1:10:00 hours 54mA

	Fitting Function: y(x)=a*exp(b*x)+c

	Parameters:
                        a = -1.52896e+01 +-  7.29900e-02
                        b = -1.30044e-01 +-  1.43900e-03
                        c =  5.15766e+01 +-  5.63300e-02

	Degrees of Freedom = 76

	Reduced ChiSquare = 0.999436

	Correlation Matrix:
                        a  1.00
                        b  0.08  1.00
                        c -0.47  0.78  1.00

	Coil.30V.TempVSTime.fit.pdf 

	Time constant : 7.7 minutes


----------------------------------------------------
Third Test

Coil under vacuum at about 50C with no volage on its leads.
Measuring PT resistance, Coil Resistance, and Time

	Pressure 
		Begin 0.030mbar
		End   0.030mbar

	File
		Name: Coil.ResDecayVSTime.out
		Columns: Coil Resistance (Omhs), PT Resistance (Omhs), Time(Minutes), Time(seconds)

	Fitting Function: y(x)=a*exp(b*x)+c

	Parameters:
                        a =  1.80588e+01 +-  7.76600e-01
                        b = -1.51347e-01 +-  1.38300e-02
                        c =  3.10635e+01 +-  7.62900e-01

	Degrees of Freedom = 15

	Reduced ChiSquare = 0.508097

	Correlation Matrix:
                        a  1.00
                        b  0.51  1.00
                        c -0.84 -0.85  1.00

	Coil.TempDecayVSTime.fit.pdf 

	Time constant :  6.6 minutes


Coil resistance versus temperature

	Fitting Function: y(x)=a+b*x

	Parameters:
                        a =  4.69785e+02 +-  2.40779e+00
                        b =  1.65947e+00 +-  5.84476e-02

	Degrees of Freedom = 16

	Reduced ChiSquare = 1.00003

	Correlation Matrix:
                        a  1.00
                        b  0.99  1.00

	CoilResVSTemp.fit.pdf 

	Calibration: ~0.0021 C/Ohms