Form 2S9jfS3 : SBB 
VX-3/633g-3420 
Department of Comme 
A. wetmore! 
l&utmtx of ^tanharhc 
REPORT 
i'H.';.: R ^ on- ; 'V.' i- '':V 
1 Paulin Altimeter ; V 
submitted by 
Smithsonian Institution 
(JSr, A* V/etmore) 
Washington, D. C. 
on 
April 2, 1930, 
Description of Instrmaent . 
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B.3,Serial Ho. 3420 
Ident. Ho* D 1097 
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Maker: C. $. Johansson, Sweden. 
Range: -900 to 9700 feet. 
Least Graduation: 10 feet. 
Least Reading: 5 feet 
Diameter of dial: 3 1/8 inches 
Weight: 11 ounces 
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: V'I- Tests ■ 
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Scale error:test at room temperature . The instrument was 
adjusted so that it read approximately zero at a pressure of 
29.90 inches of mercury. It was then clamped under a bell jar : 
with an external connection to the center button so that the 
tendenoy pointer could be set at zero. The pressure was changed 
at an average rate of 1000 feet in five minutes. The pressure 
was held constant at the'test points for three minutes and the 
reading of the instrument compared to the reading of a mercury 
barometer connected to the bell Jar* The pressure was decreased 
from 30.63 inches to 21.06 inches of moroury and then increased 
to 29.67 inches of mercury. h-RRR- 
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Results of Tests 
For the series of ascending and descending readings the 
following table gives the true pressures as determined from the 
mercury barometer and the correction to be added algebraically 
to the reading to obtain the true altitude according to the 
altitude-pressure relation of Table 51 of the Smithsonian 
Meteorological Tables, Edition of 1918. 
