Fig. 5-1. Linearization of output
Example: 0-25% Sulfuric acid
Table 5-3.
Code 4-20 % H
2
SO
4
mS/cm Default
Output mA Service Service mS/cm
code 55 code 35
0 4.0 0.00 0 0
5 4.8 1.25 60 50
10 5.6 2.50 113 100
15 6.4 3.75 180 150
20 7.2 5.00 218 200
25 8.0 6.25 290 250
30 8.8 7.50 335 300
35 9.6 8.75 383 350
40 10.4 10.00 424 400
45 11.2 11.25 466 450
50 12.0 12.50 515 500
55 12.8 13.75 555 550
60 13.6 15.00 590 600
65 14.4 16.25 625 650
70 15.2 17.50 655 700
75 16.0 18.75 685 750
80 16.8 20.00 718 800
85 17.6 21.25 735 850
90 18.4 22.50 755 900
95 19.2 23.75 775 950
100 20.0 25.00 791 1000
Concentration Output function is done in de following order:
• Set OUTP.F. (Service Code 31) to table
• Set the Concentration range in % (Service Code 55)
• Set table values (%output and Conductivity values) in TABLE (Service Code 35)
mA
5-5. mA output functions
Code 31 OUTP.F For the SC202 the output may be chosen as linear to input, or configured in a
21 point table to a particular linearization. Enable the table setup in code 31, and
configure the table in code 35.
Code 32 BURN Diagnostic error messages can signal a problem by sending the output signals
upscale or downscale (21 mA or 3.6 mA). This is called upscale or downscale
burnout, from the analogy with thermocouple failure signaling of a burned-out or
open circuit sensor. The pulse burnout setting gives a 21 mA signal for the first
30 seconds of an alarm condition. After the “pulse” the signal returns to normal.
This allows a latching alarm unit to record the error. In the case of the EXA the
diagnostics are extensive and cover the whole range of possible sensor faults.
* Only when the HART communication is disabled the downscale output signal
is 3.6 mA. When HART communication is enabled the output signal is 3.9 mA.
Code 35 TABLE The table function allows the configuration of an output curve by 21 steps
(intervals of 5%). The following example shows how the table may be configured
to linearize the output with a mA curve.
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