English to Swedish Tech/Engineering Chemistry; Chem Sci/Eng

In calibration of gas detecting equipment certain specific gas mixtures are used: zero gas and span gas.
So what are zero and span in swedish in this context?
actual definitions:
zero gas: a purified gas that has an impurity concentration below the minimum detection limit of the analytical instrument
span gas: a special gas mixture to calibrate and test gas detection equipment ensuring correct readings
actual sentences:
Note: the Oxygen sensor does not require a zeroing procedure. Background air (20.9%Vol
oxygen) can be used to span the oxygen sensor in place of a compressed air cylinder
(20.9%Vol oxygen).
When the zero gas reading is stable use ‘’ to confirm zero calibration.
Connect the regulator to the span gas cylinder.