Calibration of PCI-MIO-16E-4 card

I have a new PCI-MIO-16E-4 card which requires calibration. I ran the
comedi_calibrate program and the voltages recorded by the card were much
improved. However there is still an offset of -0.04 to + 0.02 V ( input
voltage source less comedi voltage) for one range I will use (-10 V to +10 V).
For the other range (0 to 10 V) there is an offset of 0 to -0.04 V. I have
also noticed that the card seems to require re-calibration every time the PC
is switched on. Is this normal?

I attach the output of the calibration program.

If anyone has ideas on how I can improve on this I would really appreciate
hearing from them.

Thank you

June 


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*                                 	*     
* June Morland				*
* University of Bern			*
* Institute of Applied Physics		*
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* CH 3012 Bern				*
* Switzerland				*
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* Tel +41 (0)31 631 8678		*
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* Email june.morland_at_mw.iap.unibe.ch	*
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Warning: device not fully calibrated due to insufficient information
Please send this output to <ds_at_schleef.org>
$Id: comedi_calibrate.c,v 1.24 2002/01/22 09:32:28 ds Exp $
Driver name: ni_pcimio
Device name: pci-mio-16e-4
Comedi version: 0.7.64
ai, bipolar zero offset, low gain
offset -0.01618(25), target 0
caldac[0] gain=-1.435(21)e-5 V/bit S_min=206.697 dof=254
caldac[1] gain=-1.02035(21)e-3 V/bit S_min=542.994 dof=254
caldac[3] gain=2.43(21)e-6 V/bit S_min=241.218 dof=254
ai, bipolar zero offset, high gain
offset 1.79(16)e-5, target 0
caldac[0] gain=-1.39831(13)e-5 V/bit S_min=690.218 dof=254
caldac[1] gain=-5.1042(13)e-6 V/bit S_min=484.197 dof=254
ai, bipolar voltage reference, low gain
offset 4.97146(24), target 5
caldac[0] gain=-1.443(21)e-5 V/bit S_min=231.633 dof=254
caldac[1] gain=-1.00901(21)e-3 V/bit S_min=1182.07 dof=254
caldac[3] gain=-5.8880(21)e-4 V/bit S_min=1124.89 dof=254
ai, unipolar zero offset, low gain
offset 0.06372(28), target 0
caldac[0] gain=-1.413(21)e-5 V/bit S_min=220.849 dof=254
caldac[1] gain=-1.01684(36)e-3 V/bit S_min=205.821 dof=179
caldac[3] gain=1.19122(39)e-3 V/bit S_min=649.586 dof=170
ao 0, zero offset, low gain
offset -0.01786(25), target 0.002442
caldac[0] gain=-1.438(21)e-5 V/bit S_min=261.713 dof=254
caldac[1] gain=-1.02067(21)e-3 V/bit S_min=495.017 dof=254
caldac[3] gain=2.49(22)e-6 V/bit S_min=234.501 dof=254
caldac[4] gain=-1.1612(21)e-4 V/bit S_min=264.257 dof=254
caldac[5] gain=-7.7704(21)e-4 V/bit S_min=669.134 dof=254
ao 0, reference voltage, low gain
offset -8.8(26)e-4, target -0.001221
caldac[0] gain=-1.246(21)e-5 V/bit S_min=221.871 dof=254
caldac[1] gain=-1.02063(21)e-3 V/bit S_min=516.031 dof=254
caldac[4] gain=-1.3868(21)e-4 V/bit S_min=352.461 dof=254
caldac[5] gain=-7.7804(21)e-4 V/bit S_min=608.171 dof=254
ao 1, zero offset, low gain
offset -0.01313(25), target 0.002442
caldac[0] gain=-1.375(21)e-5 V/bit S_min=213 dof=254
caldac[1] gain=-1.02035(21)e-3 V/bit S_min=525.479 dof=254
caldac[3] gain=1.92(21)e-6 V/bit S_min=250.666 dof=254
caldac[7] gain=-1.1429(21)e-4 V/bit S_min=290.537 dof=254
caldac[8] gain=-7.7286(21)e-4 V/bit S_min=793.763 dof=254
ao 1, reference voltage, low gain
offset -0.01454(26), target -0.001221
caldac[0] gain=-1.410(21)e-5 V/bit S_min=255.855 dof=254
caldac[1] gain=-1.02025(21)e-3 V/bit S_min=518.661 dof=254
caldac[3] gain=1.85(21)e-6 V/bit S_min=226.78 dof=254
caldac[7] gain=-1.3898(21)e-4 V/bit S_min=276.703 dof=254
caldac[8] gain=-7.7247(21)e-4 V/bit S_min=720.654 dof=254
caldac[9] gain=-1.2812(21)e-4 V/bit S_min=261.898 dof=254