June 22, 2004
MEMORANDUM
To:
Eric Tishman, Rosco Laboratories
From:
Alan Kao
Subject:
Addendum to Time-and-Distance Guidelines for Rosco Delta 3000
In the report
Development of Time-and-Distance Guidelines For Use Of Theatrical Smoke
Equipment: Rosco Delta 3000
dated May 2004 (“T&D Guideline report”), ENVIRON developed
time-and-distance (T&D) guidelines for the use of four Rosco fog fluids in the Delta 3000 fog
machine. These T&D guidelines were based on release durations of 30 seconds for the 100%
and 50% settings, and 60 seconds for the 10% setting. This memorandum provides an
adjustment factor (AF) for using different release durations than 30 or 60 seconds.
ENVIRON conducted additional testing with the Delta 3000 fog machine to evaluate the effect
on the T&D guidelines using different release durations. Release durations ranging from 5 to 60
seconds were evaluated. Figures 1 and 2 show the percent change from the 30-second and 60-
second T&D guidelines observed at different release durations. A linear regression was
performed on each plot to develop the following equations for:
For 100% and 50% settings:
AF = (1.36
×
RD + 59) / 100
For the 10% setting:
AF = (0.93
×
RD + 44) / 100
where:
AF
= adjustment factor (unitless)
RD
= release duration (sec)
For using the Rosco Delta 3000 at release durations that differ from those on which the T&D
Guideline report was based, the T&D guideline value from Table 2 can be multiplied by the
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