The OxyTrans-PSS is a portable transmitter with sampling system and case that is an easy to use, accurate and economical way to measure oxygen at trace and percent levels in gases. The included OxyTrans oxygen concentration transmitter has a simple display and one point calibration that allows quick startup. The OxyTrans-PSS uses a special fuel cell to measure the oxygen concentration. The sensor meets industrial requirements for accuracy, sensitivity and operating life. The measuring cell is modular and made of stainless steel. A defective measuring cell can be repaired by replacing the defective part only, rather than the complete unit.