BS 1756-4:1977

Foreword
Cooperating organizations
Specification
1. Scope
2. References
3. Determination of moisture
4. Determination of oxides of sulphur: propan-2-ol
     (isopropanol) method
5. Determination of oxides of sulphur: direct method
6. Determination of sulphuric acid dew point
7. Determination of carbon monoxide (<0.5%): macro
     iodine pentoxide method
8. Determination of oxides of nitrogen: modified
     Saltzman method
10. Determination of oxides of nitrogen: phenol-
     disulphonic acid method
Tables
1. Correction factors: saturated gas volume to dry
     volume at 0 deg C and 1013.25 mbar
2. Precision of analysis of carbon monoxide
     concentrations in test laboratories
3. Selection of sample volume
4. Vapour pressure of 40% sodium dihydrogen phosphate
     solution
Figures
1. Typical absorption train for the determination
     of moisture in flue gases
2. Midvale tube
3. Diagram of absorption apparatus for determination of
     sulphur trioxide and sulphur dioxide
4. Sampling probe with water jacket for the
     determination of sulphur oxides
5. Filter tube for moisture or SO2/SO3 determinations
6. Saturating tube for SO2/SO3 determinations
7. Sulphur trioxide collecting vessel
8. Suitable pump protection column for SO2/SO3
     determinations
9. Suitable form of expansion chamber for SO2/SO3
     determinations
10. Sampling train for the direct determination of
     sulphur trioxide and sulphur dioxide
     (diagrammatic)
11. Sulphur trioxide collector
12. Alternative forms of sulphur trioxide collector
13. Apparatus for washing condensed sulphuric acid
     from collector
14. Sulphuric acid dew point detector
15. Probe for sulphuric acid dew point measurement
16. Temperature measuring and conductivity circuit
     for the dew point apparatus
17. Compressed air filter for the dew point apparatus
     (diagrammatic)
18. General layout of the dew point apparatus
     (diagrammatic)
19. Iodine pentoxide train for the macro determination
     of carbon monoxide
20. Multi-stage absorption bubbler
21. Apparatus for the micro determination of carbon
     monoxide (diagrammatic)
22. Gas burette for the micro carbon monoxide apparatus
23. Iodine pentoxide heater for the micro carbon
     monoxide apparatus
24. Iodine absorption tube for the micro determination
     of carbon monoxide
25. Gas pipette for carbon monoxide determination

Determination of moisture content, sulphuric acid dew-point, carbon monoxide, oxides of sulphur and oxides of nitrogen.