Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 57)

<4. COMMISSIONING OF pH/ORP>
4-3
IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
4.1 Sensor setup
“Sensor type” setup is determined by the sensor to be connected to the instrument. Select one of
the following three sensor types:
pH: Only pH is measured. The glass electrode (input 1) is connected to terminal 15
and the reference electrode (input 2) is connected to terminal 13.
ORP: Only Redox is measured. The metal electrode (input 1) is connected to terminal 15
and the reference electrode (or glass) (input 2) is connected to terminal 13.
pH + ORP: Both pH and ORP are measured simultaneously. The glass electrode is connected
to terminal 15, the reference electrode to terminal 13, and the metal electrode to
terminal 14. This setup also allows rH to be measured.
For best results, connect a liquid earth to terminal 14. For details of the wiring connections,
see Section 2.5.1. If there is no liquid earth, the sensor diagnostic function is disabled; set all of
“Impedance 1 too high/low” and “Impedance 2 too high/low” in “Error configuration” to Off so that
no related error is caused.
NOTE
The selection of “Sensor type” determines the menu structure throughout the instrument.
When pH + ORP is specified as the sensor type, the object under measurement will be displayed
at the top of “Measurement setup.”
If the sensor type is changed from pH to ORP, part of the relevant setup is reset, requiring
reconfiguration.
When ORP is specified, and when an ORP sensor doesn’t have any temperature element,
set both of “Temperature too high/low” in “Error configuration” to Off so that no related error is
caused. (Refer to the section 4.4.) Without temperature input, a temperature shown on the Main
display or the Home display is the maximum or the minimum temperature of the temperature
element’s range set on the Temperature settings. Setting in “Display setup” can make
temperature value on the display not to be displayed. (Refer to the section 4.7.)
4.2 Measurement setup
This section describes how to set up various parameters relating to measurements.
Measurements are performed based on the measurement parameter setup.
For measurement setup, part of the menu structure of settable items changes depending on the
“Sensor type” selected in “4.1 Sensor setup.”
4.2.1 Measurement
If “pH” or “ORP” is selected in “Sensor type,” a measurement type does not need to be selected
and it is not displayed.
If “pH + ORP” is selected in “Sensor type,” five measurement types can be selected for the
“Measurement” item at the top of the Measurement setup screen. Select a suitable measurement
type for the application.
Moreover, associated items are added to parameters in “Error configuration,” “Display setup,”
etc.; check the setting condition of each item.
PH
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