Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 63)

<4. COMMISSIONING OF pH/ORP>
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IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
4.2.7 Sensor diagnostic settings
This screen is used to set items relating to sensor diagnostics displayed on the screens invoked
by pressing .
Gauges are displayed for only parameters that have been enabled in “Sensor diag. settings.”
Parameters set to Disable are provided with a bar display.
The setting parameters include Input 1 imp., Input 2 imp., Progress time, and Heat cycle.
When input impedance is set “High” (section 4.2.5), “FINE” value can be changed. When input
impedance is set “Low”, its “High limit” and “Low limit” will be the limits for diagnostic.
It is also possible to set the “Bad limits” of the progress time and heat cycle and the “Heat cycle
temp” and “Heat cycle time” of the heat cycle.
4.3 Output setup
The general procedure is to first define the function of the output, Output or Simulate. Then, set
the process parameters associated with the output. On the Output, an output of measured value
is selected. On the Simulate, a simulation value can be set.
And, the parameters for HOLD function can be set on this setting.
l Output
The output signal is a current value specified by the following parameters.
Process parameter
The available process parameters depend on the selected “Sensor type” on the Sensor setup
and the selected “Measurement” type on the Measurement setup.
The output of the selected process parameter is shown as a bar on the bottom of the Main
display or the Home display. And its parameter symbol (for example, PH1 or Diff-pH) is shown
above the bar, too. When a selected process parameter is displayed as a measurement value,
the top left number or character is turned to be white number or character on black background
(for example, or ). (Refer to the section 1.3.)
Process parameters can be selected from among:
pH1, Temperature 1, and ORP1: 1st module’s measured values
pH2, Temperature 2, and ORP2: 2nd module’s measured values
Calculated*1 and Redundant*2: special output based on two inputs
*1: Refer to the section 4.8, Calculated data setup.
*2: Refer to the below.
Calculated data and Redundant system are available when two modules are installed on the
instrument. And, these functions are available when the “pH” (or the parameter including pH)
or the “ORP” is selected on the “Sensor type” setting and the “Measurement” type setting. The
parameter for the 1st module and the 2nd module should be the same. For wrong selection, an
error is given.
When the process parameter is set at “Calculated” of “Redundant”, don’t change the “Sensor
type” or the “Measurement” type. If it is changed, the process parameter will go back to the
default.
PH
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