=RedDwarf=

I would like to know the name of the device used to examine the eyes and the retina such as used to check a diabetics eyes for changes. Photos/pictures can be taken. I will describe what they look like. They have a chin rest and eye piece which focuses on the eye and they have a lens to magnify. A person will sit in front of it and put their chin on the chin rest so that the operator can take the pictures of the retina. I have searched and searched but cannot find the name of it. I have checked ophthalmology devices, companies selling such devices to opticians etc but have not found the name of it. Can anyone name the item that I am thinking about? [EDIT] Further searching turned up a slit-lamp (biomicroscope) which looks vaguely similar but not 100% identical because the one I am thinking about looked quite a lot larger, more sturdy and robust. The one that I remember had no digital camera and used a camera to take the picture but this was of the iris rather than the retina. If anyone can name anything similar which I can check out it might help me identify the name of the device.

Having a rack inside the tank? That would absorb far too much ultrasonic energy which I do not want or need. What is needed is some way to hold the test tubes in place from outside the tank. That is where I am stuck for ideas. I think that there must be something which people in the chemistry field might know of something suitable which I am not aware of. The commonly available stuff I do not think will fulfil my requirement. What I have looked at on a few sites did not have anything suitable. I posted to this forum because I thought it most suitable being equipment for amateur science but the more professional sub-forums might of got more views by people who might of been more able to offer advice.

Yes, the test tube(s) need to be held elevated inside an ultrasonic cleaner tank while operating and nothing must touch the bottom of the tank. The less that is in the tank the better because anything in it will absorb ultrasonic energy which I want to keep to a maximum.

I am looking for some sort of stand that can hold multiple 25mm diameter test tubes inside an ultrasonic tank. I would like to hold at least 4 test tubes, preferably 6. They must be held at the same height and be easily removable. Currently I have been using 2 heavy retort stands with 2 four pronged clamps per stand. This is a lot less than ideal because the clamps are held one above the other which does not work well because of the significant height difference. I would like something which works better, ideally without costing me large amounts of money. I would think that anyone with good experience in professional science might know of something which would fit my requirement. What I would like is the name of the device which might fit my requirement? BTW The ultrasonic tank size is Tank LxWxH: 302 x 152 x 150mm therefore 6 test tubes would be pushing it a bit. 3 x 2 along the tank length