Handheld O2 analyzer

Can you solve this tech challenge on measuring oxygen content? Challenge: Fred is looking for an instrument to measure the oxygen content of some vials. The amount of headspace in the vial is very crucial for his testing procedure. He needs an accurate meter that can read very low values and is easy to use. He doesn't need any fancy, expensive functionality—he just needs to measure and store a few data points. Fred said, “The simpler the better!” What would be the best meter for his application? CheckMate II O2 benchtop analyzer (model 86490-20) measures from 10 ppm to 100% with an accuracy of 1% of reading, and it can log more than 10,000 test results. Handheld O2 analyzer (model 10360-20) measures from 0.1 to 100% with 1% accuracy, and has no datalogging capability. CheckPoint O2 analyzer (model 86490-00) measures from 0 to 100% with 0.1% from 0 to 5% and 2% from 5 to 100%. It also stores up to 10 readings to be recorder later. Benchtop O2 analyzer (model 10360-60) measures from 0.1 to 100% with 0.1% accuracy; has no datalogging capability. See the answer