A nitrogen-gas filled cyer with a maximupref Either a 105 mmmeter tet gauge (model PR-20) featuring an anti-parallax mirre same circuitry is used in both readout units. The only differen tt gauge: the PR-20 has a di

aluge while the PR-20D has a digital gauge. Readingen once the transdr tubings are filled with ge pressustabied., or a high-precision digital test gauge (model PR-20D).14 000 kPa. The cylindpressure is indicated by a pressure ggomatic constaw contv that givecise and highly repeatesults (available only bew  0–100 kPa measment ge).