Apa silivauiga:
1. Fa'amatalaga atoatoa ma mea eseese;
2. Saʻo maualuga maualuga, e oʻo atu i le ± 0.1mm;
3. Lelei tulaga lelei, susulu lelei;
4. Malosi tete'e corrosion, maualuga tensile malosi ma le vaivai malosi;
5. Faʻamautu vailaʻau faʻapipiʻi, uamea mama, maualalo mea e aofia ai;
6. Lelei afifi, tau lelei;
7. E mafai ona faia e aunoa ma le calibration.