Array Focus Calibration - 12/16/99

Here are the steps for taking and reducing data for the array focus voltages vs. step equations
Performed on 12/16/99 on a warm cryostat.

1. instruction.txt - Instruction to J.Rayner on how to take the data. I (tony) actually took the data.

2. 4 samples were taken using testStepper's AfocData command. Format is: step voltage_mean voltage_std

raw1.dat - Positive direction from 0 to 300000.
raw2.dat - Positive direction from 0 to limit. (limit hit just after 325000).
raw3.dat - Negative direction from 0 to -300000.
raw4.dat - Negative direction from 0 to limit. (Limit hit at -302643).

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

3. Using a linear regression, I offset the the steps from the raw data so 0 step is very close to 0 volts.

For raw2.dat, subtract 2619.6474 from the steps. New data is pos.skv
For raw4.dat, subtract 1040.7462 from the steps. New data is neg.skv

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

a = -0.00179431181
b = 4.298283049E-6
c = -5.895146564E-12
d = 1.14823961E-16
e = -3.869035688E-22
f = 8.786704213E-28
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 = -792.459819
b = 265794.3487
c = -109063.2158
d = 25466.935
e = -2480.065352
f = 16.52949367
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 = 0.001574615333
b = 4.272991761E-6
c = 5.976971287E-12
d = 9.936242797E-17
e = 3.329663294E-22
f = 7.68707926E-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.

a = 836.797494
b = 262747.6234
c = 74946.6978
d = -11142.22004
e = -12892.2302
f = -2265.333134
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: -300000 to 325000.
The voltage ranage limits should be from about -2.80 to 3.6 volts.