Final answer:
The two gauges that are permanently installed on cryotainers are pressure and quantity gauges. The pressure gauge measures gauge pressure, while the quantity gauge indicates the level of cryogenic liquid inside the container.
Step-by-step explanation:
The two gauges that are permanently installed on cryotainers are pressure and quantity gauges. The pressure gauge measures the pressure inside the cryotainer relative to atmospheric pressure, which is known as gauge pressure. When the cryotainer's internal pressure is higher than the atmospheric pressure, the pressure gauge indicates a positive value. Conversely, when used in applications like vacuum chambers where the pressure inside is less than atmospheric pressure, the gauge may indicate a negative value.
The quantity gauge indicates the level of the cryogenic liquid within the container. Monitoring both pressure and quantity is crucial to ensure the proper functioning and safety of the cryotainer. Understanding the difference between gauge pressure and absolute pressure is also essential. Absolute pressure is the sum of gauge pressure and atmospheric pressure. By using these gauges, one can monitor the state of the cryogenic material stored in cryotainers effectively