These are the measured sky levels (DN per pixel measured over the whole chip) for the different chips for the frames used in the version 2 data reduction. Frame EXPTIME chip 1 chip 2 chip 3 chip 4 u31p0211t.c0h 2500.0 0.781 2.448 2.891 2.762 u31p0216t.c0h 2500.0 0.791 1.606 2.397 2.054 u31p0218t.c0h 2500.0 0.668 1.490 2.013 2.013 u31p021at.c0h 2500.0 0.534 1.180 1.664 1.568 u31p021kt.c0h 1500.0 0.272 0.905 1.172 0.800 u31p021mt.c0h 1100.0 0.494 0.710 0.607 0.699 u31p031et.c0h 2500.0 0.811 2.354 2.572 2.552 u31p031gt.c0h 2500.0 0.854 2.376 2.480 2.326 u31p031it.c0h 2500.0 0.650 1.572 1.927 1.772 u31p0717t.c0h 1300.0 0.426 0.403 0.554 0.745 u31p071at.c0h 1400.0 0.425 0.477 0.517 0.555 u31p0305t.c0h 2500.0 0.766 2.006 2.317 2.257 u31p030at.c0h 2500.0 0.781 2.513 2.879 2.755 u31p030ct.c0h 2500.0 0.757 2.285 2.743 2.729 u31p030et.c0h 2500.0 0.784 2.058 2.480 2.569 u31p030gt.c0h 2500.0 1.048 1.816 2.326 2.329 u31p030jt.c0h 2500.0 0.642 1.868 2.338 2.218 u31p030lt.c0h 2300.0 0.522 1.495 1.555 1.661 u31p030ot.c0h 1800.0 0.501 0.953 1.030 0.998 u31p0208t.c0h 2500.0 0.965 2.599 3.169 3.146 u31p020bt.c0h 2200.0 0.765 1.862 2.184 2.317 u31p020et.c0h 2000.0 0.620 1.179 1.458 1.608 u31p020ht.c0h 1800.0 0.398 1.236 1.462 1.177 u31p020jt.c0h 1300.0 0.637 1.224 1.163 0.730 u31p020lt.c0h 1500.0 0.277 0.704 0.885 0.743 u31p021cn.c0h 2400.0 0.502 1.345 1.608 1.576 u31p021ft.c0h 2000.0 0.417 1.274 1.434 1.243 u31p021it.c0h 1300.0 0.416 0.656 0.671 0.780 u31p050bt.c0h 1600.0 0.282 0.619 0.567 0.545 u31p050dt.c0h 1500.0 0.399 0.558 0.648 0.773 u31p050ft.c0h 1400.0 0.516 0.668 0.848 0.557 u31p050ht.c0h 1500.0 0.336 0.467 0.507 0.508 u31p050jt.c0h 1300.0 0.197 0.374 0.613 0.486 u31p050lt.c0h 2400.0 0.404 0.827 1.303 1.103 u31p040at.c0h 1700.0 0.487 0.692 0.589 0.720 u31p040ct.c0h 1400.0 0.327 0.698 0.522 0.682 u31p040et.c0h 1100.0 0.482 0.308 0.711 0.425 u31p040ht.c0h 1000.0 0.502 0.316 0.961 0.538 u31p0503t.c0h 2900.0 0.588 0.932 1.421 1.322 u31p0505t.c0h 2400.0 0.446 1.127 1.195 1.263 u31p0507t.c0h 2000.0 0.272 0.759 0.850 0.796 u31p0509t.c0h 1700.0 0.510 0.697 0.812 0.934 u31p050nt.c0h 2400.0 0.468 1.300 1.401 1.335 u31p050ut.c0h 2400.0 0.521 1.261 1.424 1.276 u31p070at.c0h 2400.0 0.262 1.108 1.187 1.121 u31p070dt.c0h 2400.0 0.431 0.823 0.921 1.274 u31p070gt.c0h 2400.0 0.596 0.767 0.938 1.149 u31p081wt.c0h 1900.0 0.388 0.515 0.595 0.638 u31p030vt.c0h 1300.0 0.531 0.403 0.818 0.895 u31p030xt.c0h 1000.0 0.258 0.346 0.631 0.391 u31p0401t.c0h 2400.0 0.482 1.065 1.394 1.224 u31p0403t.c0h 2200.0 0.362 0.832 1.220 1.230 u31p0405t.c0h 1800.0 0.532 0.759 0.799 0.954 u31p0408t.c0h 1600.0 0.239 0.752 0.629 0.971 u31p070nt.c0h 2400.0 0.530 0.693 0.970 1.104 u31p070zt.c0h 2200.0 0.366 0.816 0.834 0.630 u31p0711t.c0h 1900.0 0.501 0.826 0.797 0.525 u31p0714t.c0h 1800.0 0.488 0.515 0.627 0.700 u31p0609t.c0h 1400.0 0.563 0.608 0.503 0.746 u31p060bt.c0h 1300.0 0.328 0.623 0.857 0.525 u31p080at.c0h 2100.0 0.322 0.744 0.698 0.614 u31p080ct.c0h 2000.0 0.395 0.726 0.857 0.534 u31p080ft.c0h 1800.0 0.439 0.497 0.643 0.694 u31p080it.c0h 1500.0 0.509 0.676 0.581 0.538 u31p080lt.c0h 1600.0 0.432 0.755 0.620 0.739 u31p040mt.c0h 2400.0 0.463 1.035 1.190 1.336 u31p040ot.c0h 2400.0 0.575 0.946 1.448 1.285 u31p040tt.c0h 2400.0 0.604 0.818 1.348 1.287 u31p0601t.c0h 2900.0 1.041 0.693 1.077 1.047 u31p0603t.c0h 2300.0 0.432 0.701 1.113 0.885 u31p0605t.c0h 2200.0 0.311 0.810 0.695 0.854 u31p0607t.c0h 1800.0 0.429 0.887 0.619 0.688 u31p081it.c0h 2200.0 0.353 0.887 0.613 0.645 u31p081kt.c0h 2300.0 0.419 0.916 0.971 0.746 u31p081nt.c0h 2000.0 0.415 0.803 0.571 0.594 u31p081qt.c0h 2400.0 0.450 0.817 0.741 0.623 u31p081st.c0h 1400.0 0.572 0.283 0.581 0.555 u31p0212t.c0h 2700.0 0.912 5.605 5.688 5.526 u31p0215t.c0h 2700.0 1.255 5.661 5.828 5.693 u31p0217t.c0h 2700.0 1.569 5.699 5.989 5.745 u31p0219t.c0h 2200.0 1.345 4.661 5.021 4.992 u31p021jt.c0h 2100.0 0.732 4.321 4.402 4.357 u31p021lt.c0h 2200.0 0.682 4.618 4.566 4.352 u31p021nt.c0h 2600.0 0.811 5.411 5.419 5.263 u31p0304t.c0h 2600.0 1.205 5.707 5.771 5.655 u31p0306t.c0h 2600.0 0.849 5.538 5.630 5.371 u31p0309t.c0h 2700.0 1.152 5.768 5.887 5.714 u31p0201t.c0h 2700.0 1.402 5.819 5.933 5.926 u31p0207t.c0h 2700.0 1.612 6.134 6.443 6.048 u31p020it.c0h 1800.0 0.542 3.652 3.729 3.677 u31p020kt.c0h 2300.0 0.803 4.716 4.887 4.672 u31p020mt.c0h 2000.0 0.572 3.975 3.952 4.076 u31p010vp.c0h 2100.0 0.696 4.360 4.367 4.203 u31p010xp.c0h 2300.0 0.679 4.784 4.720 4.567 u31p010zp.c0h 2700.0 0.764 5.502 5.631 5.498 u31p0110p.c0h 2700.0 1.107 5.789 5.779 5.600 u31p0112p.c0h 2600.0 0.935 5.352 5.478 5.296 u31p0113p.c0h 400.0 0.518 1.716 1.747 1.516 u31p0116t.c0h 400.0 0.165 1.254 1.437 1.799 u31p0118t.c0h 700.0 1.601 5.282 5.904 5.670 u31p011bt.c0h 700.0 1.286 4.702 5.387 5.128 u31p011dt.c0h 500.0 0.764 3.280 3.177 2.625 u31p011ft.c0h 900.0 1.816 7.365 7.806 7.882 u31p011gt.c0h 600.0 1.442 3.773 4.167 3.771 u31p0114t.c0h 2600.0 0.834 5.344 5.458 5.324 u31p0117t.c0h 2600.0 0.866 5.338 5.443 5.237 u31p011at.c0h 2600.0 0.698 5.376 5.393 5.237 u31p011et.c0h 2600.0 0.970 5.411 5.483 5.260 u31p011ht.c0h 1400.0 0.522 2.588 3.042 2.904 u31p080vt.c0h 2300.0 2.088 9.408 9.572 9.186 u31p080yt.c0h 2300.0 2.378 9.748 10.068 9.847 u31p0811t.c0h 2300.0 2.241 9.501 9.726 9.580 u31p0814t.c0h 2300.0 2.411 9.375 9.682 9.490 u31p0817t.c0h 2300.0 2.503 9.059 9.312 9.151 u31p0103t.c0h 2100.0 0.613 4.405 4.507 4.180 u31p0105t.c0h 2700.0 0.859 5.489 5.651 5.325 u31p0108t.c0h 2700.0 0.698 5.555 5.489 5.421 u31p010bt.c0h 2700.0 1.062 5.360 5.589 5.286 u31p010dt.c0h 2700.0 0.965 5.607 5.619 5.467 u31p0801t.c0h 1400.0 1.349 5.715 6.217 5.819 u31p0802t.c0h 1400.0 1.364 5.689 5.777 5.677 u31p0804t.c0h 1100.0 1.441 4.739 4.618 4.691 u31p0805t.c0h 1400.0 1.474 6.712 7.093 6.581 u31p0807t.c0h 1000.0 1.307 4.461 4.761 4.765 u31p0808t.c0h 1100.0 1.090 5.230 5.458 5.177 u31p020ot.c0h 2600.0 1.136 5.416 5.441 5.137 u31p020rt.c0h 2600.0 0.831 5.508 5.421 5.321 u31p020vt.c0h 2600.0 0.752 5.362 5.438 5.273 u31p020yt.c0h 2600.0 0.808 5.312 5.415 5.264 u31p0210t.c0h 2700.0 1.011 5.566 5.691 5.476 u31p010kt.c0h 2700.0 1.134 5.557 5.773 5.785 u31p010mt.c0h 2700.0 1.347 5.651 5.826 5.675 u31p010pt.c0h 1900.0 1.386 4.079 4.190 4.264 u31p010rt.c0h 1700.0 0.970 3.589 3.671 3.594 u31p010tt.c0h 1700.0 0.731 3.539 3.653 3.467 u31p0715t.c0h 700.0 1.321 6.967 7.068 6.933 u31p0716t.c0h 1000.0 2.222 10.224 10.333 10.084 u31p0718t.c0h 1200.0 2.558 12.500 12.532 12.278 u31p0719t.c0h 1200.0 2.397 12.384 12.350 12.119 u31p071bt.c0h 1300.0 2.450 13.274 13.322 12.953 u31p071ct.c0h 1300.0 3.197 13.692 13.661 13.497 u31p071pt.c0h 1300.0 2.754 13.863 13.659 13.402 u31p071qt.c0h 1300.0 3.363 14.333 14.382 14.179 u31p071st.c0h 1300.0 2.805 13.575 13.650 13.292 u31p071tt.c0h 1300.0 3.212 14.345 14.424 14.209 u31p071vt.c0h 1300.0 2.868 13.859 13.783 13.535 u31p071wt.c0h 1300.0 3.147 14.405 14.377 14.156 u31p071zt.c0h 500.0 1.277 5.171 5.292 5.053 u31p071et.c0h 1300.0 2.418 13.235 13.252 12.857 u31p071ft.c0h 1300.0 2.737 13.811 14.052 13.644 u31p071it.c0h 1300.0 2.450 13.232 13.175 12.856 u31p071jt.c0h 1300.0 2.758 14.219 14.322 14.131 u31p071lt.c0h 1300.0 2.568 13.320 13.405 13.066 u31p071mt.c0h 1300.0 3.176 13.812 13.846 13.687 u31p030it.c0h 800.0 1.655 7.972 8.315 8.107 u31p030kt.c0h 1200.0 2.828 12.495 12.627 12.397 u31p030mt.c0h 600.0 1.545 6.029 6.260 6.046 u31p030nt.c0h 600.0 1.167 5.819 6.168 6.061 u31p030pt.c0h 800.0 1.693 8.289 8.302 8.035 u31p030qt.c0h 800.0 1.426 8.089 8.158 7.933 u31p020at.c0h 800.0 1.701 8.144 8.341 8.150 u31p020dt.c0h 700.0 1.446 6.992 7.093 7.082 u31p020ft.c0h 700.0 1.684 7.024 7.234 6.860 u31p020gt.c0h 700.0 1.436 7.087 7.213 6.899 u31p021bt.c0h 1100.0 2.497 11.204 11.341 11.079 u31p021dt.c0h 800.0 1.635 8.160 8.310 8.156 u31p021et.c0h 350.0 0.843 3.515 3.601 3.476 u31p021gt.c0h 800.0 1.848 7.925 8.284 7.884 u31p021ht.c0h 500.0 0.923 4.767 5.131 5.018 u31p0502t.c0h 900.0 1.846 9.179 9.413 9.239 u31p0504t.c0h 900.0 2.036 9.243 9.550 9.429 u31p0506t.c0h 1300.0 3.033 13.386 13.513 13.253 u31p0508t.c0h 1500.0 3.135 15.419 15.484 15.172 u31p0818t.c0h 1300.0 2.849 14.775 14.594 14.256 u31p0819t.c0h 1300.0 3.318 15.073 14.904 14.673 u31p081bt.c0h 1000.0 2.429 10.927 11.055 11.031 u31p081dt.c0h 700.0 1.551 7.273 7.536 7.424 u31p081ft.c0h 700.0 1.429 7.339 7.444 7.179 u31p081ht.c0h 700.0 1.463 7.265 7.438 7.343 u31p0701t.c0h 1200.0 2.566 12.381 12.430 12.201 u31p0708t.c0h 1300.0 2.706 13.355 13.364 13.038 u31p0709t.c0h 1300.0 2.670 13.659 13.650 13.414 u31p070bt.c0h 1400.0 2.709 14.571 14.563 14.269 u31p070ct.c0h 1400.0 3.013 14.926 14.973 14.729 u31p070et.c0h 1300.0 2.637 13.513 13.577 13.278 u31p070ft.c0h 1300.0 2.661 13.694 13.802 13.570 u31p070ht.c0h 1300.0 2.701 13.677 13.765 13.506 u31p070it.c0h 1300.0 2.946 13.889 13.800 13.457 u31p081xt.c0h 500.0 1.341 5.244 5.305 5.002 u31p081zt.c0h 700.0 1.563 7.326 7.538 7.398 u31p0822t.c0h 500.0 1.364 5.024 5.499 5.152 u31p0824t.c0h 700.0 1.735 7.523 7.660 7.475 u31p0827t.c0h 700.0 1.623 7.388 7.552 7.174 u31p0829t.c0h 700.0 1.882 7.454 7.717 7.511 u31p0402t.c0h 1300.0 3.221 13.479 13.525 13.265 u31p0404t.c0h 1400.0 3.006 14.328 14.395 14.128 u31p0406t.c0h 800.0 1.693 8.164 8.242 8.185 u31p0407t.c0h 800.0 1.533 7.952 8.003 8.120 u31p080tt.c0h 1300.0 2.763 13.665 13.591 13.334 u31p080ut.c0h 1300.0 2.987 14.463 14.517 14.195 u31p080wt.c0h 1300.0 2.646 13.903 13.817 13.517 u31p080xt.c0h 1300.0 3.146 14.498 14.506 14.315 u31p080zt.c0h 1300.0 2.862 13.876 13.994 13.596 u31p0810t.c0h 1300.0 3.307 14.372 14.445 14.163 u31p0812t.c0h 1300.0 2.842 14.944 14.771 14.523 u31p0813t.c0h 1300.0 3.459 14.581 14.653 14.420 u31p0815t.c0h 1300.0 2.860 14.323 14.364 14.021 u31p0816t.c0h 1300.0 3.398 15.081 15.401 15.091 u31p070lt.c0h 1300.0 2.798 13.468 13.615 13.243 u31p070mt.c0h 1300.0 2.712 13.697 13.869 13.611 u31p070ot.c0h 1300.0 2.945 13.635 13.746 13.544 u31p070pt.c0h 1300.0 3.290 13.663 13.753 13.599 u31p070st.c0h 1200.0 2.742 12.889 12.941 12.697 u31p070vt.c0h 1000.0 2.313 10.251 10.419 10.346 u31p070yt.c0h 1200.0 2.585 12.354 12.398 12.235 u31p0710t.c0h 1400.0 2.802 14.178 14.302 13.970 u31p0712t.c0h 800.0 1.517 8.254 8.295 7.963 u31p0713t.c0h 800.0 1.460 8.298 8.364 8.169 u31p0803t.c0h 800.0 1.797 8.307 8.416 8.175 u31p0806t.c0h 1000.0 2.164 10.321 10.543 10.375 u31p0809t.c0h 1200.0 2.613 12.572 12.664 12.371 u31p080bt.c0h 1500.0 3.041 15.572 15.603 15.181 u31p080dt.c0h 800.0 1.567 8.157 8.234 7.861 u31p080et.c0h 800.0 1.604 8.269 8.354 8.291 u31p080gt.c0h 1000.0 1.856 10.278 10.391 10.197 u31p080ht.c0h 1000.0 2.224 10.541 10.631 10.522 u31p080jt.c0h 1200.0 2.642 12.638 12.701 12.393 u31p080kt.c0h 1200.0 2.540 12.712 12.784 12.523 u31p080mt.c0h 1300.0 2.804 14.069 13.796 13.519 u31p080nt.c0h 1300.0 2.940 14.245 14.090 13.881 u31p0602t.c0h 1000.0 2.417 10.187 10.399 10.291 u31p0604t.c0h 1300.0 2.768 13.408 13.529 13.270 u31p0606t.c0h 1300.0 2.800 13.223 13.332 13.032 u31p081jt.c0h 1000.0 1.985 10.382 10.508 10.326 u31p081lt.c0h 600.0 1.222 6.078 6.243 6.151 u31p081ot.c0h 400.0 0.496 3.859 4.063 3.887 u31p081tt.c0h 700.0 1.347 7.396 7.468 7.259 u31p081vt.c0h 800.0 1.582 8.637 8.694 8.634 u31p031dt.c0h 2700.0 2.900 15.257 15.159 14.853 u31p031ft.c0h 2700.0 2.832 15.344 15.382 14.985 u31p031ht.c0h 2700.0 3.257 15.375 15.411 15.130 u31p031jt.c0h 2700.0 3.493 15.409 15.550 15.185 u31p071gt.c0h 1200.0 3.096 10.838 11.200 11.039 u31p071ht.c0h 1200.0 2.360 9.689 9.492 8.971 u31p071nt.c0h 1200.0 1.726 8.747 8.932 8.966 u31p071ot.c0h 1200.0 2.541 10.298 10.531 9.908 u31p030bt.c0h 2800.0 3.218 15.805 15.803 15.521 u31p030dt.c0h 2500.0 2.739 14.097 14.355 13.864 u31p030ft.c0h 2600.0 3.256 14.914 14.972 14.670 u31p030st.c0h 1900.0 2.303 10.600 10.583 10.474 u31p030ut.c0h 2400.0 2.481 13.567 13.577 13.207 u31p050at.c0h 1800.0 1.845 10.135 10.167 9.981 u31p050ct.c0h 2100.0 2.299 11.820 11.836 11.597 u31p050et.c0h 2400.0 2.453 13.763 13.510 13.228 u31p050gt.c0h 2600.0 2.844 14.702 14.566 14.298 u31p050it.c0h 2700.0 3.248 16.146 15.921 15.607 u31p050kt.c0h 2600.0 2.621 14.634 14.560 14.280 u31p081at.c0h 2200.0 4.012 16.875 16.925 16.516 u31p081ct.c0h 3100.0 5.392 23.609 23.789 23.391 u31p081et.c0h 2700.0 5.007 22.462 22.594 22.091 u31p081gt.c0h 2300.0 4.072 18.224 18.353 17.862 u31p0409t.c0h 2000.0 2.245 11.210 11.146 10.990 u31p040bt.c0h 2200.0 2.483 12.261 12.273 11.926 u31p040dt.c0h 2600.0 2.786 14.587 14.503 14.272 u31p040ft.c0h 2600.0 2.652 14.584 14.494 14.180 u31p040it.c0h 2600.0 2.624 14.622 14.498 14.164 u31p0820t.c0h 1100.0 1.687 7.813 8.113 7.708 u31p0821t.c0h 1100.0 2.149 8.561 8.746 8.547 u31p0825t.c0h 1100.0 1.552 7.605 7.763 7.557 u31p0826t.c0h 1100.0 2.308 8.889 9.107 8.720 u31p082at.c0h 1400.0 2.065 9.458 9.624 9.555 u31p082bt.c0h 1400.0 2.644 10.829 10.989 10.689 u31p050mt.c0h 2700.0 2.835 15.164 15.322 14.900 u31p050ot.c0h 2700.0 2.792 15.274 15.270 14.919 u31p050qt.c0h 2700.0 3.312 15.370 15.408 15.056 u31p050tt.c0h 2700.0 3.037 15.160 15.367 14.973 u31p050vt.c0h 2200.0 2.663 12.490 12.596 12.400 u31p030wt.c0h 2600.0 2.658 14.588 14.550 14.183 u31p030yt.c0h 2600.0 2.941 14.574 14.421 14.176 u31p0315t.c0h 2600.0 2.637 14.565 14.498 14.190 u31p0318t.c0h 2600.0 2.638 14.550 14.485 14.111 u31p031at.c0h 2700.0 2.851 15.620 15.538 15.184 u31p070qt.c0h 1200.0 2.372 10.168 10.513 10.433 u31p070rt.c0h 1200.0 2.001 9.407 9.486 9.192 u31p070tt.c0h 1300.0 2.548 11.273 11.527 11.389 u31p070ut.c0h 1400.0 2.799 12.180 12.255 11.809 u31p070wt.c0h 1000.0 1.885 8.488 8.727 8.501 u31p070xt.c0h 1200.0 2.671 11.950 12.092 11.760 u31p0608t.c0h 1500.0 1.600 8.339 8.357 8.184 u31p060at.c0h 2100.0 2.382 11.968 11.996 11.691 u31p060ct.c0h 2200.0 2.344 12.361 12.335 12.075 u31p040lt.c0h 2600.0 2.622 14.573 14.500 14.217 u31p040nt.c0h 2700.0 2.850 15.252 15.320 14.867 u31p040pt.c0h 2500.0 2.771 13.798 13.981 13.699 u31p040st.c0h 2700.0 2.997 15.117 15.218 14.868 u31p040ut.c0h 2400.0 3.219 13.709 13.676 13.395