Complete A Scada Calculation; Complete A 4-20 Ma Output Test - Hach 2200 PCX User Manual

Table 3 Sample size reference table (flow = 100 mL/min)
Count Period (seconds)
6
12
15
18
Table 4 Divisors for full scale value determination (> 2µm)
Channel Divisor
>3µ 3.4
>4µ 8
>5µ 15.6
>6µ 27

Complete a SCADA calculation

When the values are specified after each analog output for the lower limit, the upper limit and the full
scale, the SCADA programmer enters the values for: The channel range, the upper size limit and the
full scale value. The lower limit (4 mA) will always be 0 counts. In all cases, the lower limit signal
(4 mA) will be 0 (zero) particles, the upper limit signal (20 mA) will be equal to the full scale value.
The full scale value must then be divided by the sample volume (mL sample).
For example: If the sample flow rate is 100 mL/min, a count period of 30 seconds, the sample volume
result is 50 mL. The maximum expected particle count is 1000 particles/mL. Then, the FS value =
1000 particles/mL x 50 mL = 50,000 CH0 set to cumulative particle counts > 2 μm. Refer to
CH Lower Upper
0 2 0
1 5 0
2 7 0
3 10 0
1
Divide by the value that value equals the mL sample used to calculate the full scale value.
2
Divisor applied from
Complete a 4–20 mA output test
Do the test that follows to make sure that the analog current scaling of 4–20 mA data acquisition
instruments (e.g., SCADA, PLC, etc.) are connected to the instrument with the analog I/O card
installed. This procedure will push 4 mA or 20 mA from the instrument and an amp meter in series
with the 4–20 mA loop in the line verifies the current flow.
1. Set the instrument power to off.
2. Connect the programming cable between the computer and the connector J1-RS232 on the
instrument interconnect card. Use the RS485 connection.
3. Supply power to the instrument.
4. Send the ASCII command "load" to the instrument terminal to change the operating configuration.
Note: The word "load" is case sensitive. All letters in the word must be lower or upper case characters.
5. Get access to the change menu within 30 seconds for the instrument configuration. Make sure to
send the "load" command within 30 seconds after the unit power is set to on.
Sample Size (mL)
10
20
25
30
Channel
>7µ
>8µ
>9µ
>10µ
Table 5 SCADA calculation
Full scale Label at SCADA
5000 >2 μm
2
3200 >5 μm
2
1166 >7 μm
2
400 >10 μm
Table 4 on page 23
Count Period (seconds)
24
30
48
60
Divisor Channel
43 >11µ
64 >12µ
90 >14µ
125 >15µ
4 mA =
0
0
0
0
Sample Size (mL)
40
50
80
100
Divisor
166
216
343
422
Table
1
20 mA = Divide by
5000 50
3200 50
1166 50
400 50
English 23
5.