Dear Oscar,

1000°C is  a far hard stuff.

The attached link may help you a little bit.

Good luck.

https://www.setra.com/blog/how-to-select-a-sensor-for-high-temperature-environments

You might consider some metal  tube attached to the reactor, intended to radiate part of the extreme heat. A pressure sensor mounted to the end of the tube will experience lower temperatures while still reading the correct pressure value.

Hi Oscar,

In addition to what Dreher has stated above, you can consider some mechanical arrangement to transfer the heat/pressure information outside the 1000oC environment to a lower temperature level and use the existing high temperature rated pressure sensor such as that you have already explored for 350oC.

What I mean to say that it may be a sensor direct but some combination of electromechanical or even electro-optic arrangement would be a best solution to your requirement.

Best Luck!