What kind of material can I shine a red laser sensor through?

I have a height level laser sensor that will be used to measure the height of grains on a grain conveyor. This area has lots of dust so I need to mount the laser inside an explosion proof enclosure. This enclosure will have a lens where the laser shines through and I was wondering what material I should use for the lens. I have been told sapphire is a good choice when it comes to lasers. The travel distance for the laser will be approximately 0.2 to 1 metre at all times.

The laser has the following specifications:
Light source: Laser red, class 1 (EN 60 825-1-2007)
Light spot diameter: typ. Ø 15 mm at 10 m distance

The rest of the specifications can be found in the following data sheet:
http://www.sensorsincorporated.com/uploaded/Doc/DT50 Data Sheet.pdf

What you're looking for is not a lens per se, but a window. Plain glass will work just fine unless what
you're trying to measure is almost at the distance limit. Then you would need AR coated glass. Since
you're going to be cleaning dust off it all the time though the AR coating won't last too long. Might I also
suggest making the enclosure water tight so the window can be cleaned with water or glass cleaner to
minimize scratching.

Glass isn't explosion proof... Try plexiglass or break proof. I know what you mean. A family by my family's farm had a grain silo blow when the farm and surrounding area caught fire. The dust ignites pretty fast that's for sure.

How many explosions are you anticipating? Wouldn't it be easier to just replace the asploded laser when something goes boom?

cantthinkofone said:

Glass isn't explosion proof...

Click to expand...

It is if it's thick enough.

Is it true that the closer the laser beam is to the glass window the better the measurement I will get (since there is less reflection?)?