Rosemount 3300 Series high temperature and pressure probes are designed to prevent leakage and perform reliably when exposed to extreme process conditions for extended periods of time. Materials are selected to avoid stress fractures commonly induced by changes in temperature and pressure conditions. For example, aluminum oxide ceramic insulators provide electrical feed through for microwave signals while acting as impermeable barriers to the temperature and pressure conditions in the tank.

The design of the probe provides multiple layers of protection. The seal includes a temperature and pressure barrier in a flexible assembly to handle forces induced by probe movement and temperature variations. A second brazed hermetic, gas-tight seal provides another layer of protection and the entire assembly is welded into a stainless steel sleeve for total robustness.

The HTHP seal can be used even in the most extreme process conditions with temperatures up to 752 F (400 C) and pressures up to 5000 psi (345 Bar). It is available for the rigid single lead probe and the coaxial lead probe.

The hermetic seal is isolated from the process and temperature shocks, so that pressure and outside forces on the probe will not affect the integrity of the seal.

A flexible probe load and locking system compensates for stress from thermal expansion and lateral and vertical forces. It also protects and fastens the ceramics.

The ceramic insulators and graphite gaskets on the temperature and pressure seal provide a robust thermal and mechanical barrier as well as offering chemical resistance.