Yokogawa EXA DC402 Dual-Channel Conductivity Analyzer - Manual (Page 43)

IM 12D08E02-01E
5-18 Parameter setting
0
1.000
800
600
400
200
0
100
80
60
40
20
0
2 4 6 8 10 12 14 16 18 20 22 24
5-3-4. mA output functions
Code 30 *mA Select 4-20mA or 0-20mA according to associated equipment (recorders,
controllers etc.)
Code 31 *OUTP.F Note: For resistivity measurement, read resistivity in stead of conductivity.
Output mA1 Conductivity linear
(terminals 61&62) Conductivity with 21 point output table. (The table can be configured to
give an output linear to concentration, see example at the end of this
page).
Output mA2 Conductivity linear
(terminals 65&66) Conductivity with 21 point output table.
Temperature linear
PI control on conductivity (analog output control signal with proportional
and integral functions).
Direct or reverse action of the mA control output. Direct gives rising output with
rising measurement. Reverse gives falling output with rising measurement.
Code 32 *BURN Diagnostic error messages can signal a problem by sending the output signals
upscale or downscale (22mA or 0/3.5mA). This is called upscale or downscale
burnout, from the analogy with thermocouple failure signalling of a burned-out
or open circuit sensor. In the case of the EXA the diagnostics are extensive
and cover the whole range of possible sensor faults.
Code 33 *RG.mA1(2) This function sets the proportional range for the mA output control signal. The
range setting is expressed in % of setpoint.
Code 34 *tI.mA1(2) This function sets the integral time for the mA output control signal
Code 35-36 *TABL1(2) 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 W/W% curve. On the next page some other possibilities are
shown.
Code 37 *DAMP Transmission signal damping (not mA control output).
Code mA mA
Output 0-20 4-20 % H
2
SO
4
mS/cm
00 0 0 00. 4 00.0 0 00 0
00 5 1 0 4.8 0 1.25 0 60
0 10 2 0 5.6 00 2.5 113
0 15 3 0 6.4 0 3.75 180
0 20 4 0 7.2 00.0 5 218
0 25 5 00. 8 0 6.25 290
0 30 6 0 8.8 00 7.5 335
0 35 7 0 9.6 0 8.75 383
0 40 8 10.4 00. 10 424
0 45 9 11.2 11.25 466
0 50 10 0. 12 0 12.5 515
0 55 11 12.8 13.75 555
0 60 12 13.6 00. 15 590
0 65 13 14.4 16.25 625
0 70 14 15.2 0 17.5 655
0 75 15 0. 16 18.75 685
0 80 16 16.8 00. 20 718
0 85 17 17.6 21.25 735
0 90 18 18.4 0 22.5 755
0 95 19 19.2 23.75 775
100 20 20.0 00. 25 791
Fig. 5-1. Linearization of output
Example: 0-25% Sulfuric acid
Concentration (% by weight)
Output in %
Table 5-3.
Conductivity (mS/cm)
Conductivity
% Output