[sjernigan]

I think I have found the answer to my question. It appears that the cheaper ammeters will work if they are installed in series with the ground side of the tube. I guess the resistance of the tube lowers the voltage drop across the meter and lowers the danger of an arc. I'm still interested to any answers to question 1.

[bajoel78]

I think I have found the answer to my question. It appears that the cheaper ammeters will work if they are installed in series with the ground side of the tube. I guess the resistance of the tube lowers the voltage drop across the meter and lowers the danger of an arc. I'm still interested to any answers to question 1.

as far as i know, k40 laser machine from china ussualy set 99.99% power to about 15mA. this is to protect tube. i ussually cut acrylic 3mm with 30% of power and cutting speed about 16mm/min. and dont forget to adjust distance between laser lens to media that will be cut.