Why autoclave pressure gauge is 1.2 practically, but has a different amount in the saturated steam tables?

Microbiology
1

Why autoclave pressure gauge at 121°C, show 1.2 bar but Scientific resources have written 15 psi (or 1.03 bar)???

2

OK. No problem when transfer bar to psi equal result = 1.2 bar = 17.9 psi almost same result

3

Yes, maybe not important but temperature and pressure are interdependent, why the amount of the theory is 1 bar but practical amount is 1.2 bar ???

4

Finally, I discovered the solution:
The gauge pressure required will be higher than the pressure shown in the saturated steam table due to elevation above sea level.

5

please provide the reference for the same. as it is very useful.

6

Ref:

  1. Steam Sterilization Principles by Marcel Dion
  2. Autoclaves by Frank Weithöner