This page contains information on the weekly inspection of the WHT primary mirror.

Visual inspection of the primary mirror at WHT

 

Date

Weather in past period?

(rain, humidity, dust)

Appearance of

the primary

Reflectivity

Surface roughness

RMS

Action taken

Comments

Link to the image

Inspector's name
26 Feb 08 high clouds, high humidity The spots and the stains are there. There are new stains on the right side (AP3) 83.0% 76.610 CO2 cleaning All the reflectivity, scattering and surface roughness have been improved    Tibor Agocs
13 Feb 08 high clouds, high humidity The spots and the stains are there. Apart from it the mirror is in a good state. 83.8% 77.375 none CO2 cleaning is necessary (today the humidity was too high)    Tibor Agocs
29 Oct 07 high clouds, high humidity, calima The spots and the stains are there. Apart from it the mirror is in a good state. 86.7% 49.140 none The results are almost the same as from the last measurements after the CO2 cleaning.    Tibor Agocs
04 Oct 07 high clouds, high humidity, calima The spots and the stains are there. 84.1% 61.996 CO2 cleaning All the reflectivity, scattering and surface roughness have been improved    Tibor Agocs & Neil O'Mahony
24 July 07 Strong calima last week The spots and the stains are there. Surface visibly dustier than in previous inspection. 87% 57.159 CO2 cleaning Surface dust noticeably improved, reflectivity too.    Tibor Agocs & Neil O'Mahony
22 May 07    high clouds, rain,  humidity, petals were left open on the 21th of May The spots and the stains are there 87.2% 44.0 none The reflectivity and the surface roughness is still good in contempt of the spots see below Tibor Agocs
24 April 07    high clouds, humidity The spots and the stains are there (see image) 87.3% 36.6 none The reflectivity and the surface roughness is really good in contempt of the spots spots

stains

 Tibor Agocs
13 April 07    All kinds: dust, rain, high cloud, humidity Large water/dust spots all over. No water streaks.

Small opaque stains at 9 o'clock, 30-50 cm from the baffle. Looks like dirt falling from small distance (no splash).

 N/A N/A CO2 cleaning after inspection Condensation or possibly light rain. 1 month since last inspection. photo4 Neil O'Mahony
13 March 07 humidity high on some days Clean. Two small drops (5-10 mm) at 6 o'clock N/A N/A none It seemed as some kind of liquid dropped down to the mirror photo3 Tibor Agocs
28 Feb 07 humidity high on Sat and Sun during the day Clean. The spots are still there. N/A N/A none The spots are probably because of the aluminising. photo2 Tibor Agocs

21 Feb 07

 humidity (1/2 night) Clean. 3 or 4 black spots < 5mm N/A N/A Blowing, did not remove spot Oil? Too small to concern. photo1 Neil O'Mahony