In: Chemistry
Uncertainty calculation I want to determine the air density (ρ,
in kg/m3) using the following equation.
p=(1/R)*(P/T)
where
P : barometric pressure, in Pa
T: temperature, in K
R: specific gas constant for dry air, 289.7 J/(kg·K) [assume
constant has no uncertainty]
I performed a sample-to-sample experiment with 6
repetitions/samples (n = 6). I got following results:
P = 96,389 ± 167 Pa
T = 311.8 ± 2.93 K
The tags on the sensors show the barometric pressure sensor was
factory calibrated at ±2% of the actual reading, and the
temperature sensor was factory calibrated at ±2 K constantly.
QUESTION: Estimate the air density, ρ, and its uncertainty. You
need to show the procedures of your calculations. Consider two
tails 95% CI t-distribution.
Hints:
t value =2.571 (6 samples, 95% CI)
??/?? = 1/?∙?
??/?? = 1/?∙?^2