Belzelbub
Contributor
The regulator and test gasses are most likely not necessary. If you want, you can get a flow restrictor that will work with your regulator's low pressure inflator hose. You don't need it, but it's quieter in use than the plain tank valve and the tee. Calibrating in air works just fine.For what it is worth, I'm going to get the Oxycheq Expedition-X Oxygen Analyzer. It seems to me though this is not as feature rich as the Divesoft ones, I really like the flexibility offered.
I plan to get two test gas cylinders with regulators to be able to do a calibration check each time I would use it. I know that this is probably not viable for traveling, but here are the options I'm selecting to spot check the sensor:
Expedition BC Flow Restrictor
Expedition Flow Restrictor connects to the nozzle on any of the Expedition series analyzers. The flow restrictor features a standard quick disconnect to connect to low pressure inflator hoses.Reduces flow to between 2 to 4 LPM.
www.oxycheq.com
It appears that the Expedition comes with the plastic nozzle that attaches to the oxygen sensor. If not, they sell a version that includes the nozzle as well.