TE-5170DV TSP VFC 23 Operations Manual
Note that the ambient temperature is needed in degrees Kelvin to satisfy the Qa equation. Also, the
barometric pressure needs to be reported in millimeters of mercury (if sea level barometric pressure is
used it must be corrected to the site elevation). In our case the two following conversions may be
needed:
8. degrees Kelvin = [5/9 (degrees Fahrenheit - 32)] + 273
9. millimeters of mercury = 25.4(inches of H2O/13.6)
Inserting the numbers from the calibration worksheet test number one we get:
10. Qa = 1/.92408[Sqrt((3.8)(293/749.3))- (-0.00383)]
11. Qa = 1.0821573[Sqrt((3.8)(.3910316)) + 0.00383]
12. Qa = 1.0821573[Sqrt(1.48592) + 0.00383]
13. Qa = 1.0821573[1.2189831 + 0.00383]
14. Qa = 1.0821573[1.2228131]
15. Qa = 1.323
It is possible that your answers to the above calculations may vary. This is most likely due to different
calculators carrying numbers to different decimal points. This should not be an area of concern as
generally these variations are slight.
With Qa determined, the sampler H2O reading needs to be converted to mm Hg using the following
equation:
16. Pf = 25.4 (in. H2O/13.6)
where:
17. Pf is recorded in mm Hg
18. in. H2O = sampler side pressure reading during calibration
Inserting the numbers from the worksheet:
19. Pf = 25.4(6.4/13.6)
20. Pf = 25.4(.4705882)
21. Pf = 11.95294 mm Hg
Po/Pa is calculated next. This is done using the following equation: