I neglected to record the on screen temperature display over the duration of the test. However, the temperature would have been reasonably constant (no AC running during or before the test).
Here is a sample of the raw data from around the 550 second mark. You can see the data is being sampled twice per second, but apparently quite heavy filtering is being applied, so the update rate appears slower than that. The filtering is quite apparent from the spike contained within this sample. The time constant appears to be in the order of a few seconds.
550.0406, 0.485
550.525, 0.485
551.0563, 0.485
551.5406, 0.484
552.025, 0.484
552.5563, 0.484
553.0406, 0.484
553.525, 0.484
554.5422, 0.484
555.0266, 0.484
555.5578, 0.483
556.0422, 0.489
556.5266, 0.489
557.0578, 0.489
557.5422, 0.489
558.0266, 0.489
558.5578, 0.488
559.0422, 0.488
559.5176, 0.487
560.0645, 0.487
560.5488, 0.486
561.0266, 0.487
561.5578, 0.487
562.0422, 0.486
562.5891, 0.486
563.0579, 0.486
563.5385, 0.486
564.0295, 0.486
564.5608, 0.486
565.0475, 0.485
565.5787, 0.485
566.104, 0.485
566.5461, 0.485
567.0305, 0.486
567.5618, 0.486
568.0421, 0.486
568.5889, 0.486
569.5421, 0.485
570.0264, 0.485
570.5665, 0.485
571.0352, 0.485
571.5821, 0.486
572.0665, 0.486
572.5352, 0.485
573.0821, 0.485
573.5665, 0.485
574.0352, 0.485
574.5352, 0.485
575.5352, 0.485
576.0821, 0.485
576.5665, 0.485
577.0352, 0.485
577.5821, 0.484
578.0665, 0.484
578.5352, 0.484
579.0821, 0.484
579.5665, 0.484
580.0352, 0.484