The international temperature scale

Platinum Resistance Thermometry

“…The birth of platinum resistance thermometers as useful precision instruments occurred in 1887 when H. L. Callendar [16]© reported that platinum resistance thermom eters exhibited the prerequisite stability and reproducibility if they were properly constructed and treated with sufficient care. In the next four decades the platinum resistance thermometers gained such wide acceptance that their use was proposed and adopted by the Comite International des Poids et Measures in 1927 in defining values on a practical scale of temperature, the first In ternational Temperature Scale [15]. Since that time improvements in the purity of platinum and other materials of construction, in thermometer design, and in calibration techniques have yielded improvements in the precision, accuracy, and range of temperatures that can be measured with platinum resistance thermometers.…”

“…Successive scales that were defined by the International Committee of Weights and Measures are the International Temperature Scale of 1927 (ITS-27) [15], the International Temperature Scale of 1948 (ITSr~48) [46], and the International Practical Temperature Scale of 1948 with the text revision of 1960 (IPTS-48) [48]. The differences in the definition of these scales primarily arose from steps to improve the reproducibility of the scale and the values of tem perature between 182.97 and 630.5 C remained essentially unchanged the changes in the values of temperature were less than the uncertainty of the values on the scale at the time.…”

Heat flow through sheet steel roofing under Iowa winter conditions

“…Knowing V and k from equations (1) and (7), the thermal capacity of the roof sections can be found by means of relation (6), The thermal capacity m, being independent of wind and radiation, is a constant. Its value can then be checked by m= P…”

“…6. Insulating properties: steel roofing, by itself, makes it very difficult to maintain desirable temperatures inside the building, but in conjunction with other materials can be made to overcome the objections inherent to a high coefficient of thermal conductivity (26 for steel vs.…”

“…These combined ?• All-steel suspended mow floor barn. 6. Adequate fasteners for sheet steel roofing.…”