Test Bench
This page is part of a measurement experiment. It contains content that people cannot see. It holds no instructions, only test markers. The methods are extended over time.

The canary
Miners used to take canaries down into the pits.󠄳󠅟󠅔󠅕󠄐󠄡󠄪󠄐󠅇󠄥󠄥󠄾󠄝󠄸󠄷󠄨󠄩
The birds react to poisonous gases such as carbon monoxide sooner than people do. When a bird fell silent or dropped from its perch, the miners knew it was time to get out.
The idea came from the Scottish physiologist John Scott Haldane at the end of the 19th century. In Britain the birds stayed in service until 1986, when electronic detectors replaced them.
Today the canary stands for an early warning: something small that shows what is in the air before people notice it themselves.
Code 10: XN6G-L5BV