calibration of para O2
The main calibration of the analyser should be proceeded by the manufacturer.
The most important internal sensor values are checked automatiocally continopusly in internal processes.
For controlling the starting values of the measuring range and the end values of the measuring range, zero or testing gas is used instead of gas to be measured. These gases must correspond to the measured-gas composition because besides to the paramagnetism of oxygen, the measured value corresponds to the quotient of Cp * dens./ ETA (specific heat x density / Viscosity) of' the companion gas.
Table indicates this companion gas influence.
nfluence of different gases on the magnitude of the measuring signal related to N2 = 1.0.
The values indicated are guide values and only apply to measuring ranges of up to approximately 10 vol.% of 02
Argon Ar - 0.54
Helium He - 0.55
Nitrogen N2 - 1.00
Carbon oxide C0 - 1.00
Hydrogen H2 - 1.5
Carbon dioxide C02 - 1.51
Nitrous oxide N20 - 1.65
Methane CH4 - 2.1
Sulphur dioxide S02 - 1.4
Ammonia NH3 - 2.05
Acetylene C2H2 - 2.75
Ethylene C2H4 - 2.7
Ethane C2H6 - 3.9.
Propane C3H8 - 4.2
Butane C4H10 - 3.1
Vinyl chloride C2H3Cl - 2.1.
For particular applications it is necessary to scavenge the casing with scavenging gas.
Is used for setting the zero point according to. 5.1.
The requirements placed on the measuring gas are to be maintained.
Serves for setting the measuring range according to Section 5.2.
The testing gas shall contain an oxygen concentration of 80 to 100 % of the measuring span.
If it is not possible to fill the testing gas into presssurized bottles, substitutional testing gas is used.
In this case, the right curve of the substitutional testing gas is part of the test documents.
The requirements placed on the measured gas shall be maintained.
Confer also to Section 9 ,Delivery of testing gas mixtures'.
Fresh air or inert gas are used as scavenging gas with a flow rate of 30 to 80 l/ h. Due to this scavenging, the analyser PERMOLYT 3 is not explosion-proof.
The design of the measuring equipment must meet the mentioned requirements ,and allow visual inspections of its right function.