Hach 900 MAX, Инструкция по эксплуатации инструмента

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Page 136
How to Calculate Pulses/Counts
8990apdx_pulsecounts.fm
Appendix D
2. Calculate t .
3. Multiply Q x t x 10 .
Therefore, the value entered for
INTV = _ _ _ _ CNTS
is 39.
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 .
2. Calculate t .
3. Multiply Q x t x 10 .
Therefore, the value entered for
INTV = _ _ _ _ CNTS
is 50.
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 .
2. Calculate t .
3. Multiply Q x t x 10 .
Therefore, the value entered for
INTV = _ _ _ _ CNTS
is 240.
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.
t
a
n
---
1440 min
96 samples
-------------------------------
15 min/sample
= = =
0.26 mgd 15 min/sample
×
10
×
39
=
Q
Average Flow Rate
Maximum Flow Rate
------------------------------------------------------
70 gpm
210 gpm
----------------------- 0.33 gpm = = =
t
a
n
---
480 min
32 samples
------------------------------- 15 min/sample = = =
0.33 mgd 15 min/sample
×
10
×
49.5 =
Q
Average Flow Rate
Maximum Flow Rate
------------------------------------------------------
0.25 cfs
1 cfs
---------------------
0.25 cfs
= = =
t
a
n
---
2,880 min
30 samples
-------------------------------
96 min/sample
= = =
0.25 cfs 96 min/sample
×
10
×
240
=