Purpose of optical coupling gel

[tim.hbn]

Hi Luuk

Thank you very much indeed for your offer and sorry for the delay in getting back to you. I have been very busy.

I have actually aready purchased the stuff I found on Amazon.

Kind regards

Tim

[kotarak]

For what is worth - high viscosity clear silicone fluid is sold also in hobby stores and on eBay as fluid for oil shock absorbers and as differential fluid in high-end RC cars.
I actually tested both - the thick silicone grease and the clear differential fluid and got a bit better result with the fluid - like a tenth of a percent or two but i dont think is significant and hard to tell if the small difference is due to the coupling or other factors. The fluid is crystal clear while the grease is has a bit of cloudy / milky tint - almost like the aerogel look.

Here is the fluid on ebay - a bottle will last you for dozens of detectors - [dead link removed - Steven]

[tim.hbn]

Hi Andrey

Thank you very much indeed for your very helpful reply and I am very sorry for my delay in thanking you.

Kind regards

Tim