Accurate tyre gauge

[WF]

Hi guys and gals  as a newbie im not sure if this has been covered  im looking for an accurate tyre gauge to carry on my trips  have bought various types but have yet to get 2 similar readings  most differ quite dramaticaly
any suggestions

 

[lonerider]

 

[Obi -Wan]

 

[Pom]

 

[Adventurer]

 

[luke]

 

[Jacko]

 

[Welsh]

 

[shark_za]

 

[Welsh]