Ultrasonic waterproof protection material

Hello ,
In my project i am using ultrasonic US-100 due to its low power consumption and price.

Now i came to problem when started to thinking about the product material design , This sensor is not design to work in outdoor environment , after research I made on the internet I Understood that there is no material where the ultra sound waves can go trough, But guess what ?
There is Ultrasonic waterproof products for sale.

My question is if any one knows which materials is used here and how the ultra sound waves can pass trough them ?

The products :

JSN-B02 (ER-SP0433B02)

JSN-SR04T

USTR40-14A

I am about to get this materials and try them with the ultrasonic US-100 module ,
Will it work ?
Is there is any difference in technology used between them and ultrasonic US-100 or HC-SR04 ?

Thanks !

You need to have some sort of coupling medium that has characteristics to water - there are various oils etc. that can work, but the problem is you need to start with a transducer that is designed to be submerged in something. In the past, I used silicone to bond a transducer to the inside of the hull of my boat where there was only one layer of fiberglass and was able to get pretty reasonable results “looking” through the fiberglass while under way (most of the hull is double layer with flotation in it so you can’t go through there). The bottom line though is you need to start with something that can handle being submerged in oil or whatever so it correctly couples to the water.

gpsmikey:
You need to have some sort of coupling medium that has characteristics to water - there are various oils etc. that can work, but the problem is you need to start with a transducer that is designed to be submerged in something. In the past, I used silicone to bond a transducer to the inside of the hull of my boat where there was only one layer of fiberglass and was able to get pretty reasonable results "looking" through the fiberglass while under way (most of the hull is double layer with flotation in it so you can't go through there). The bottom line though is you need to start with something that can handle being submerged in oil or whatever so it correctly couples to the water.

Hi gpsmikey and thanks for the reply , Unfortunately I don't understand how your answer is connected to my question ... I have asked about which materials is used in the products examples I gave that Ultra sound waves can pass trough ?

stavbodik:
Hi gpsmikey and thanks for the reply , Unfortunately I don't understand how your answer is connected to my question ... I have asked about which materials is used in the products examples I gave that Ultra sound waves can pass trough ?

You need to start with a transducer that can handle being coupled (submerged) in a liquid, then you need some liquid that has similar characteristics to water - the closer it is to the water in characteristics, the better coupling (less reflections etc.) you get. Seems to me I have heard of using a silicone oil in the past, but it has been a while. You may even be able to use something like mineral oil.

You can get cheap car-reversing units which have 4 waterproof transducers. No law prevents you
buying a unit and cutting the leads to the sensors!

MarkT yes this is exactly what I am about to do… I will buy some of this sensors and check which material is used there.

gpsmikey excuse me but none of this items looks to me like any liquid, I did marked in green the material which I would like to know what they are made from :

What is the materials used in this products ? plastic/metal ? is it any kind of oil? not looks like mineral/silicon oil …or maybe I missed something ? and how do ultra sound waves not reflects by them ?