angle tightning

[sms78]

hey guys how do you use a torque angle gauge cos ive got one but never used it . do you use it with a torque wrench or afterwards with a normal rachet . I ask this because with the diesel injector bolts is 90 and then 90 again which i dont under stand ? why not just tighten it to 180 ? Do you tighten it to 90 then reset it then 90 again or do you have to wait for a while then do it again . Also do you have to check anything once the engine is hot ? sorry for all the questions

 

[television]

Isnt the first pull the torque and the next to move the bar to another 90º