Calibrate in Air 20.9%
Hold sensor with plug
Assemble DIN Kit.
Oxygen reading should still read 20.9% +/- 1 on the last digit.
Gently open cylinder until a soft hiss is heard.
Leave open for 5 seconds then turn the cylinder off.
After 10 seconds turn cylinder on again for 5 second.
The reading may go higher, then drop back, due to flow generating pressure.
When reading stops dropping the O2 level has been measured.
IF in doubt repeat from step 3.
Always check calibration has not moved.
If it has moved repet from step 1.