Purpose: To calculate the time weighted average (TWA) to a chemical over a given time period.			Citations with documentation. 33.01.02	Sriram & Svirbely 1999
conversion	enter
gram molecular weight of substance		grams
TLV (mg per cubic meter air)		mg/(m^3 air) equals	0.05	ppm
data	enter
Are you trying to estimate the time weighted average for a chemical exposure? (Y or N)		:-):-):-)
number of different concentrations (enter from 1 to 8)		:-):-):-)
chemical exposure during	ppm	hours
first period				25
second period				12
third period				12
fourth period				12
fifth period				12
sixth period				12
:-):-):-)				0
:-):-):-)				0
calculate	result
data complete?	Yes
evaluation appropriate?	Yes	:-):-):-)
time weighted average for an 8 hour period	10.625	ppm