How to calibraye uv?
Why r these tests performed?
What chemicals r used in calibration and why r they used

How about NOT using chat speak and use proper capitalization, and punctuation.

People who have to use chatspeak can't understand technical things.

THere are also rules for homework too if you had taken time to read them.

Since you take as much time reading rules as you do forming proper questions... here is a link.

https://www.askmehelpdesk.com/math-sciences/announcement-font-color-ff0000-u-b-read-first-expectations-homework-help-board-b-u-font.html