Teledyne 4700 Pocket Manual page 78

4700 Refrigerated Sampler
The steps can be summarized in the equation
below.
÷ (Q
I
samp
Note
The equation requires similar units for Q
That is, the volume and flow rate units must use the
same basic unit (cubic feet and cubic feet per second,
gallons and gallons per minute, etc.). If they are
dissimilar, convert the units before applying them to the
equation.
Example 1 – Consider a flow meter
programmed to output 20 mA at 1,000 liters per
minute, the peak flow rate of the channel. If
you are required to collect a sample every
10,000 liters, you would enter 50 flow pulses
according the equation.
10000 liters ÷ (1000 liters/min ÷ 5) = 50 pulses
Example 2 – Consider a flow meter
programmed to output 20 mA at 20 cubic feet
per second. If you are required to collect a
sample every 2400 cubic feet, you would enter
10 flow pulses according the equation.
2400 cu ft ÷ (20 cfs ÷ 0.08333) = 10 pulses
Example 3 – Consider a flow meter
programmed to output 20 mA at 8 mgd (million
gallons per day) and you are required to collect
a sample every 10,000 gallons. Because the
base units are dissimilar, you first must convert
3-30
÷ F ) = Number of pulses
max time
and I
max samp
.