Am I being paid too low for LvL 2 Ultrasonic Testing? $23/hr

Hello, I work for an industrial gas company testing gas cylinders with a UE machine from Hexagon Digital Wave. I was flown out to Colorado in May for recertification but this is my 2nd time doing this job at the same company as a level 2 ultrasonic tester.

Currently I make $23.75 an hour as a Level 2, the workload is nearly impossible as I have a daily quota of 40 large cylinders, calibrating and maintaining a very old and worn machine, changing valves, and stamping test dates/kicking out the cylinders. I am the only one at my company who is certified, the company has tried hiring on a second tester with each newhire quitting 2 weeks into coming back from cert training, wasting 10k+ investments.

I want to ask what the general workload and wages look like at other companies and if I am being severely underpaid for what I am undertaking.