What Do My Pressure Test Results Mean?

[sankim]

I had my 116234 pressure tested at private watch repair store on this past weekend. According to the slip they gave me it looks to have been done on a Proofmaster M V2. 10, with the following results:

Test pressure: +3.0 bar
Maximum deformation: +24.48um
Tightness value: +0.2 %/min
Test1 okay

They recommend to visit certified service center because of Tightness value score. Can I know 'Tightness value: +0.2 %/min' and should I go to service center because of this?

Thanks in advance