Abstract: A system including a sensor and a sensor holder. The sensor includes an inlet port for receiving a gas sample and an outlet port for exhausting a portion of the gas sample. The sensor generates an output signal indicative of an oxygen concentration of the gas sample. The sensor holder removably receives and contains the sensor and includes an inlet port for communicating the gas sample to the sensor and an outlet port for receiving the exhausted portion of the gas sample from the sensor. The inlet port of the sensor holder is aligned and sealably interfaced with the inlet port of the sensor such that the inlet ports defining a common inlet bore. The outlet port of the sensor holder is aligned and sealably interfaced with the outlet port of the sensor such that the outlet ports defining a common outlet bore.