Array Focus Calibration - 01/13/00

Here are the steps for taking and reducing data for the array focus voltages vs. step equations
Performed on 01/13/00 on a cold cryostat.

1. instruction.txt - Instructions on how to I took the data.

Positive hardware limit trigger at: 313106
Negative hardware limit trigger at: -296261

2. Two samples were taken using testStepper's AfocData command. Format is: step voltage_mean voltage_std

raw1.dat - Positive direction from 0 to limit. (Limit hit at 313106).
raw2.dat - Negative direction from 0 to limit. (Limit hit at -296261).

raw.gp - gunplot script to produce graphs.
raw.ps - postscript output from gnuplot.
raw.pdf - PDF version of raw.ps.

3. Convert the text data for import into my RegressionAnalyzer application.

Converted raw1.dat to .skv format: pos.skv
Converted raw2.dat to .skv format: neg.skv

4. pos.skv was input into RegressionAnalyzer to obtain these coefficients for volts = f(step) for step > 0.

a = 0.001485338738
b = 4.790665341E-6
c = -9.288558697E-12
d = 1.493343871E-16
e = -5.069249881E-22
f = 1.076768382E-27
pos.gp is the gnuplot script used create the pos.ps (postscript) and pos.pdf (PDF) graph.

5. pos_t.skv is the same data with x,y tranposed. The coefficients for step = f(volts) for volts > 0.

a = -2068.814187
b = 245944.684
c = -91923.26161
d = 17884.99208
e = -769.6607777
f = -139.3147189
pos_t.gp is the gnuplot script used create the pos_t.ps (postscript) and pos_t.pdf (PDF) graph.

6. neg.skv was used by RegressionAnalyzer to obtain these coefficients for volts = f(step) for step < 0.

a = 0.007388485132
b = 4.6880558E-6
c = 8.425187609E-12
d = 1.215113197E-16
e = 4.133287597E-22
f = 9.032058324E-28
neg.gp is the gnuplot script used create the neg.ps (postscript) and neg.pdf (PDF) graph.

7. neg_t.skv is the same data with x,y tranposed. The coefficients for step = f(volts) for volts < 0. Note I added the following point (-4,-350000) before the fit of neg_t.dat so the curve is better after -2.65 volts.

a = -66.84140123
b = 247791.9112
c = 76057.25043
d = 4628.385596
e = -3089.756591
f = -499.5566671
neg_t.gp is the gnuplot script used create the neg_t.ps (postscript) and neg_t.pdf (PDF) graph.

8. all.gp plots the data and function for volts = f(steps). View all.ps (postscript) or all.pdf (PDF) graph.

9. For the application the software limits for steps are: -295000 to 310000.
The voltage ranage limits should be from about -2.66 to 3.45 volts.