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APPENDIX 1 EQUILIBRIUM TIME FOR TRACER INJECTION NOTICE : The material in this appendix is an official part of SEMI F15 and was approved by full letter ballot procedures. A1-1 A1-1.1 If a trace r gas is injected at a con…

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10 Related Documents
29 CFR 1910.1000 Code of Federal Regulations,
Title 29, Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C. 20402.
ACGIH American Conference of Governmental
Industrial Hygienists, 6500 Glenway, Building D-7,
Cincinnati, OH 45211-4438, (513)661-7881. Industrial
Ventilation - A Manual for Recommended Practice,
20th ed. ISBN: 0-936712-65-1.
American Industrial Hygiene Association 345 White
Pond Drive, Akron, OH 44320, (216)873-2442.
Workplace Environmental Exposure Level Guides.
ASTM American Society for Testing and Materials,
1916 Race Street, Philadelphia, PA 19103. ASTM
Standard E741-83 (Determining Air Leakage Rate by
Tracer Dilution).
BOCA Building Officials and Code Administrators
International Inc., 4051 West Flossmoor Road, Country
Club Hills, IL 60478-5795, (708)799-2300. National
Fire Prevention Code.
Grot, R.A. and P.L. Lagus “Applications of Tracer
Gas Analysis to Industrial Hygiene Investigations,”
Industrial Hygiene News, May 1991.
Orcutt, J.R. “Characterization of Hazardous Gas
Releases by Tracer Gas Simulation,” Hazardous
Assessment and Control Technology in Semiconductor
Manufacturing, ACGIH, Cincinnati, OH, 1988.
SBCCI Southern Building Code Congress
International, 900 Montclair Road, Birmingham, AL
35213-1206, (205)591-1853. Standard Fire Prevention
Code.
Tubby, R.L. “Tracer Gas Testing of Secondary
Exhaust Systems on Hazardous Gas Enclosures,” SSA
Journal, Vol. 5, June 1991.
UFC Uniform Fire Code. International Conference
of Building Officials and Western Fire Chiefs
Association, 5360 South Workman Mill Road, Whittier,
CA 90601. 1988 Edition, ISSN 0896-9736.
SEMI F15-93 © SEMI 1993, 2004 4
APPENDIX 1
EQUILIBRIUM TIME FOR TRACER INJECTION
NOTICE: The material in this appendix is an official part of SEMI F15 and was approved by full letter ballot procedures.
A1-1
A1-1.1 If a tracer gas is injected at a constant rate into
an enclosure that possesses a constant ventilation rate,
the concentration as a function of time is given as
C(t) = (F/q) [1 - exp{-(q/V)t}] (A1 -1)
where C t Concentration within the enclosure
F Injection rate of tracer gas
q Ventilation rate of enclosure
V Volume of enclosure
t Elapsed time since initiating injection
A1-1.2 Note that the term (q/V) contained in the
exponential is the air change rate. In order for the
concentration C(t) to be constant, the exponential term
must be approximately zero. This is generally taken as
the time when the exponential term is equal to e
-3
. The
time at which this occurs can be found by setting (q/V)t
= 3 and solving for t. Thus,
(q/V)t = 3 A1- 2
from which it follows that the equilibrium time is given
as,
t 3/(q/V) (A1- 3)
t = 3(V/q) (A1-4)
SEMI F15-93 © SEMI 1993, 2004 5
APPENDIX 2
EQUATION FOR FLOW IN A STRAIGHT TUBE
NOTICE: The material in this appendix is an official part of SEMI F15 and was approved by full letter ballot procedures.
A2-1
A2-1.1 Flow in a straight tube may be calculated if the
tube characteristics, as well as the upstream and
downstream pressures, are known. In the following, the
upstream (drive side) conditions have a subscript of 1,
while the downstream (ambient) conditions have a
subscript of 0.
M
1
2
1
P
0
P
1

2
4 f
L
D

ln
P
1
P
0

2
(A2 -1)
W=A(
1
P
1
M
1
2
)
0.5
(A2 - 2)
1
0
P
1
P
0

(A2 - 3)
where
0
0.00129 g
/
cm
3
1.4
P
Pressure dynes/cm
2
4
f
0.02
for
smooth
pipe
L
Length cm
D
Diameter cm
W
Mass Flowrate g/sec
A
Area of Flow Line cm
2
NOTE 1: Atmospheric pressure, 10
6
dynes/cm
2
, is
approximately 14.7 psia.
SEMI F15-93 © SEMI 1993, 2004 6