Sanitary science applied to buildings and public works / [Henry Adams].

  • Henry Adams
Date:
1926
Catalogue details

Licence: In copyright

Credit: Sanitary science applied to buildings and public works / [Henry Adams]. Source: Wellcome Collection.

    50/208 page 34
    humidity, and may be measured indirectly by means of a wet bulb thermometer, which is an ordinary thermometer with the bulb projecting below the nO——— DRY <a> wood or metal backing and having a piece of muslin tied round it with a piece of lamp cotton dipping into a small cup of water. The water rises in the cotton and keeps the muslin moist. The drier the air, the quicker the moisture will evaporate from the muslin, and reduce the indication of the thermometer by the ab¬ sorption of latent heat, showing a lower result than a dry bulb thermometer alongside. If the air is very damp and saturated with moisture no evaporation will take place and both ther¬ mometers will indicate alike. The term relative humidity is applied to the proportion of moisture in the air compared with complete saturation, stated as a percentage. The following table will enable the relative humidity to be determined from the indications of a compound dry and wet bulb thermometer :— Fig. 9.—Dry and wet bulb thermometers. Dry Thermometer. Difference between Dry and Wet Thermometer F.° 1 2 3 4 5 6 7 8 F.° Relative Humidity, Saturation being 100. 40 92 84 76 68 60 53 45 38 50 93 87 80 74 67 61 55 50 60 94 89 84 78 73 68 63 58 70 95 9i 86 81 77 72 68 64 The most suitable temperature in a room is on the average 600 F,, but at the same time the wet bulb thermometer should
    digitised image 1
    digitised image 2
    digitised image 3