Pressure pot to measure the O2 oxygen sensors ( Analytical Industries PSR-11-39-MD )

My oxygen sensors (Analytical Industries PSR-11-39-MD) was old. It was so close times to see how their Liniarität under reproducible conditions and behaves under pressure. I need a cheap small pressure chamber . So fast times in the scrap-box seen, and for almost zero cost of a chamber built. Construction period approximately 2 hours.