test bed
1. An environment used exclusively for testing. The phrase can refer to a software program or to a physical location outfitted with instruments. Please use the app in this test bed, and let us know if it crashes. I've been in the test bed all day, but everything seems to be working properly now.
2. A frame or base that has an engine or other piece of equipment attached to it for testing purposes. How is the test bed working today? Any progress?