The required purity of the gases is defined by the contamination limits given below. The following gases shall be available for operation:
(a) Purified nitrogen (contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0,1 ppm NO) (b) Purified oxygen (purity > 99,5 per cent vol O2)
