measuring laser intensity

[chris75]

good morning
I'm a math and physics teacher and semi-beginner in holographic work.
I need an instrument for measuring laser intensity and decide time exposure etc.
can you give me some hint? I have a HeNe laser 2mW.
BEst regards
Christian Bonfanti

[jrburns47]

Maybe this?
https://ebay.us/m/JWF02c

[chris75]

thanks
there is also a more economic instrument?
cheers
Chris