Hach 900 MAX Instrument Manual page 138

Appendix D
Page 136
How to Calculate Pulses/Counts
2. Calculate t.
a 1440 min
t
= -- - = ------------------------------ - =
n 96 samples
3. Multiply Q x t x 10.
×
0.26 mgd 15 min/sample
Therefore, the value entered for
Example 4
You want to collect 32 samples over an 8-hour period.
Average Flow Rate = 70 gpm (average flow rate over the 8-hour period)
Maximum Flow Rate = 210 gpm
a = 480 minutes
1. Calculate Q.
Average Flow Rate
Q = ----------------------------------------------------- -
Maximum Flow Rate
2. Calculate t.
a 480 min
t = -- - = ------------------------------ - =
n 32 samples
3. Multiply Q x t x 10.
×
0.33 mgd 15 min/sample
Therefore, the value entered for
Example 5
It is desired to collect 30 samples over a 2-day period.
Average Flow Rate = 0.25 cfs (average flow rate over the 48-hour period)
Maximum Flow Rate = 1 cfs
a = 2,880 minutes
1. Calculate Q.
Average Flow Rate
Q = ----------------------------------------------------- -
Maximum Flow Rate
2. Calculate t.
a 2,880 min
t = -- - = ------------------------------ - =
n 30 samples
3. Multiply Q x t x 10.
×
0.25 cfs 96 min/sample
Therefore, the value entered for
You will notice from the previous five examples that the average and
maximum flow rate can be expressed in any units, i.e. mgd, gpm, cfs, etc.
However, express the average and maximum flow rate in the same units for
any given situation.
15 min/sample
×
10 39
=
INTV = _ _ _ _ CNTS
70 gpm
= ---------------------- - = 0.33 gpm
210 gpm
15 min/sample
×
10 = 49.5
INTV = _ _ _ _ CNTS
0.25 cfs
= -------------------- - = 0.25 cfs
1 cfs
96 min/sample
×
10 = 240
INTV = _ _ _ _ CNTS
is 39.
is 50.
is 240.
8990apdx_pulsecounts.fm