Teledyne 6712SR - Manual (Page 109)

6712SR Refrigerated Sampler
Section 5 Extended Programming
5-21
Figure 5-3 Variable-Volume Scenario
5.11.2 Calculations when
Using an External Flow
Meter
The highest possible SAMPLE VOLUME value is determined by
the minimum volume required for analysis and the least
expected flow rate over the sampling duration. To calculate the
number of pulses at this high end of the range, you should know:
• the least expected flow volume that will pass the flow
measurement point
• the flow volume interval between each flow pulse from
the external flow meter
• the minimum composite sample volume required for
analysis. Allow for duplicates and spillage.
These factors would be applied to the following equation.
From the scenario we can apply the factors for the equation.
Because the SAMPLE VOLUME entry must be in whole
numbers, 16.7 is rounded down to 16. It is important to note that
this number is inversely proportional to the amount of volume
collected. Rounding up would result in less volume collected.
The lowest possible SAMPLE VOLUME value is dependent upon
the highest expected flow and the available bottle volume. To cal-
culate the number of pulses or volume at this low end, you should
know:
• the greatest expected flow volume that will pass the flow
measurement point
• the flow volume interval between each flow pulse from
an external flow meter
• the available bottle volume for sample collection.
9400 ml
Hours
Lea
st E
xpe
cte
d F
low
Gr
ea
tes
t E
xp
ec
ted
Fl
ow
3000 ml
0 1 2 3 4 5 6 7 8
666,667 gal
500,000 gal
SAMPLE VOLUME:
10 ml FOR EVERY
___ PULSES
(Least Total Flow Vol) / (Flow Pulse Vol)
(Minimum Required Vol) / (10 ml per unit)
= 10 ml for every __ pulses
(500,000 gallons) / (100 gallons per pulse)
(3,000 ml / 10 ml)
= 10 ml for every 16.7 pulses