Chilly cathode gauges are precise from ten−2 Torr to 10−9 Torr. Ionization gauge calibration is very delicate to building geometry, chemical composition of gases being measured, corrosion and surface area deposits. Their calibration is often invalidated by activation at atmospheric pressure or very low vacuum. The composition of gases at https://keeganpmdui.elbloglibre.com/26013933/bourdon-tube-plastic-or-painted-steel-case-gauge-no-further-a-mystery