From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Report from the National Physical Laboratory on the examination and calibration of a Fahrenheit scale thermometer.
| Identifier | ExFiles\Box 156\1\ scan0052 | |
| Date | 20th December 1933 | |
| COPY. NATIONAL PHYSICAL LABORATORY. TEDDINGTON REPORT. On Examination of Fahrenheit Scale Thermometer. --------- PHYSICS DEPARTMENT. Thermometer No. 2182. Type:- Bi-metallic, dial indicating. Dimensions of dial:- 12 1/2 in. x 12 1/2 in. Name on Thermometer:- Corfield Ltd., London. Range:- -4° to 124°F.{Mr Friese} Divided to:- 2°F.{Mr Friese} Limit of accuracy of test:- ±0.5°F.{Mr Friese} The thermometer was mounted with its dial horizontal and with the bi-metallic element completely immersed in a bath of well stirred liquid. It was then compared with the Standard Thermometers of the National Physical Laboratory and the results of the comparison are shown in the following table:- | Thermometer Reading | Observed Correction to thermometer reading | True Temperature | | :--- | :--- | :--- | | 20.0°F | -0.2°F | 19.8 ±0.5°F | | 32.0 | 0.0 | 32.0 " | | 50.0 | -0.4 | 49.6 " | | 70.0 | -0.4 | 69.6 " | | 90.0 | -0.4 | 89.6 " | | 110.0 | -0.4 | 109.6 " | Note I. The temperature scale in use at the Laboratory is the International Temperature Scale which, in the range covered by this Report is based on the following fixed points:- Boiling point of oxygen ... -182.97°C. Freezing point of water ... 0°C. Boiling point of water ... 100°C. Boiling point of sulphur ... 444.60°C. Note II. The statement of limits incorporated in the last column of the table indicates the accuracy to which the corrected readings may be considered reliable. For example, if the corrected reading is given as 10.2 ±0.1, the correct value lies between 10.2 +0.1 (i.e. 10.3) and 10.2 -0.1 (i.e. 10.1). Note III. Observations taken on rising and on falling temperatures were found to be in agreement to within the limit of accuracy of the test. Note IV. The thermometer does not function at temperatures above 117°F.{Mr Friese} Date 20th December 1933. Reference Th.16339. A.H.Davis for Director. Wt 11835A 2m-9-32 WFP Ltd. NPL Admin. 17 | ||