Today I dismounted the Optris 640i thermocamera on the east ZnSe WE viewport of the HR mirror surface (#66865) and installed it on the same viewport of WI tower (ZnSE). I contacted Federico who kindly came to WI base tower to verify the position of the magnetometer after the intervention.
Here are the images of the WI mirror surface (the one facing the WE payload) done with the Optris 640i thermocamera:
- Fig. 1 shows the WI mirror surface with the ITF unlocked;
- Fig. 2 shows the mirror with the ITF locked in CARM_NULL;
- Fig. 3 shows the temperature measurements of three diffrerent areas of the mirror (in CARM_NULL): the highest part of the mirror ("area 1") is hotter and has a temperature of about 20.3°C. In the middle, there are two cold spots and they measure around 19.3°C ("area 2"). The lowest part of the mirror has a temperature of about 19.8°C. I couldn't find any point absorbers present on the mirror. However, this seems strange compared with the last measurements done with the HWS in May 2023 (#60377).
- Fig. 4 shows a slightly different color bar range that gives a better visual perspective (CARM_NULL_1F). The temperature in the right upper side of the figure is the background mean temperature of the mirror surface and the temperature written in the middle of the mirror corresponds to the cold spot value.
Both ITMs should have an additional ZnSe viewport (DN63 - 57791 and 57772) with a much better viewing angle—similar to the one used for the photon calibrators on the ETMs. However, a taller tripod will be required for the thermal camera.
