Pelpro PP130-B - Page 62

OMNI-Test Laboratories, Inc.
V
s
– Average gas velocity in the dilution tunnel, ft/sec
ASTM E2515 equations (9)
Where:
v
scent
= Dilution tunnel velocity calculated after the multi-point pitot traverse at the center, ft/sec
v
strav
= Dilution tunnel velocity calculated after the multi-point pitot traverse, ft/sec
k
p
= Pitot tube constant, 85.49
C
p
= Pitot tube coefficient: 0.99, unitless
ΔP* =
Velocity pressure in the dilution tunnel, in H
2
O
T
s
=
Absolute average gas temperature in the dilution tunnel, °R; (°R = °F + 460)
P
s
=
Absolute average gas static pressure in diltuion tunnel, = P
bar
+ P
g
, in Hg
P
bar
= Barometric pressure at test site, in. Hg
P
g
=
Static pressure of tunnel, in. H
2
0; (in Hg = in H
2
0/13.6)
M
s
=
**The dilution tunnel wet molecular weight; M
s
= 28.78 assuming a dry weight of 29 lb/lb-mole
Sample calculation:
14.33
15.59
81.7 + 1/2
V
s
=
0.919 x 85.49 x 0.99 x 0.241 x -0.20
13.6
V
s
=
14.73 ft/s
*The ASTM test standard mistakenly has the square root of the average delta p instead of
the average of the square root of delta p. The current EPA Method 2 is also incorrect. This
was verified by Mike Toney at EPA.
**The ASTM test standard mistakenly identifies Ms as the dry molecular weight. It should be
the wet molecular weight as indicated in EPA Method 2.
, ASTM E2515 Equation (1)
) x
Adjustment factor for center of tunnel pitot tube placement, Fp =
Fp =
=
0.919
V
strav
V
scent
F
p
=
28.78
30.51
+
(
(
)
460
 
ss
s
avg
Ppps
MP
T
PCKFV


Control No. P-SFDK-0002, Effective date: 5/06/2016 File - 135PS040E PP70 Run 1, Tab - Example Calculations
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