In modern thermometry instruments of extreme accuracy are required, and researches have been made, especially in Germany and France, to ascertain the causes of variability in mercurial thermometers, and how such variability is to be removed or reduced.
He studied the whole subject of thermometry critically; he introduced the use of an accurate air-thermometer, and compared its indications with those of a mercurial thermometer, determining the absolute dilatation of mercury by heat as a step in the process.
Calor), to be distinguished from thermometry, which signifies the measurement of temperature.
The methods depending on change of state are theoretically the simplest, since they do not necessarily involve any reference to thermometry, and the corrections for external loss of heat and for the thermal capacity of the containing vessels can be completely eliminated.
He Paid Greater Attention To The Important Question Of Thermometry, And Extended His Researches Over A Much Wider Range Of Temperature, Namely 5° To 35° C. His Experiments Revealed For The First Time A Diminution In The Specific Heat Of Water With Rise Of Temperature Between O° And 30° C., Amounting To Four Parts In To.
The Work Of Rowland By The Mechanical Method Was The First In Which Due Attention Was Paid To The Thermometry And To The Reduction Of The Results To The Absolute Scale Of Temperature.
6, Show A Minimum At 25° C., And A Maximum At 87° C., The Values Being 9935 And 1.0075 Respectively In Terms Of The Mean Specific Heat Between O° And 100° C. He Paid Great Attention To The Thermometry, And The Discrepancies Of Individual Measurements At Any One Point Nowhere Exceed O 3%, But He Did Not Vary The Conditions Of The Experiments Materially, And It Does Not Appear That The Well Known Constant Errors Of The Method Could Have Been Completely Eliminated By The Devices Which He Adopted.
This unit is taken as being 4.180 joules per gramme-degree-centigrade on the scale of the platinum thermometer, corrected to the absolute scale as explained in the article Thermometry, Which Has Been Shown To Be Practically Equivalent To The Hydrogen Scale.
These subjects are discussed in the articles Density; Thermometry; Calorimetry; Diffusion; Conduction Of Heat; and Condensation Of Gases.
This Unit Has The Advantage Of Being Independent Of Thermometry, But The Applicability Of These Methods Is Limited To Special Cases, And The Relation Of The Units To Other Units Is Difficult To Determine.