This part of ISO 6978 specifies a method for the determination of total mercury content in natural gas using a sampling method at pressures up to 40 MPa by chemisorption on iodine-impregnated silica gel. This sampling method is suitable for the determination of mercury contents within the range of 0,1 μg/m to 5 000 μg/m in natural gas. This method is applicable to sampled gas volumes containing less than 20 mg hydrogen sulfide (absolute content) and less than a total liquid hydrocarbon condensate of 10g/m under the sampling conditions. The collected mercury is determined by measuring the absorbance or fluorescence of mercury vapour at 253,7 nm. NOTE ISO 6978-2 gives a sampling method suitable for the determination of mercury content of pipeline natural gas by amalgamation of mercury on gold/platinum alloy thread at atmospheric pressure for the range of mercury from 0,01 μg/m to 100 μg/m and for sampling at high pressure (up to 8 MPa) from 0,001 μg/m to 1 μg/m.
BS EN ISO 6978-1:2003 history
0000 BS EN ISO 6978-1:2005(2006)
2006BS EN ISO 6978-1:2005 Natural gas. Determination of mercury. Sampling of mercury by chemisorption on iodine
2003BS EN ISO 6978-1:2003 Natural gas - Determination of mercury - Sampling of mercury by chemisorption on iodine