Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 186)

<16. COMMISSIONING OF SENCOM pH/ORP>
16-3
IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
16.1 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.
ORP: Only ORP is measured. Use this setting for the ORP measurement on the basis
of a glass electrode. For the measurement on the basis of a reference electrode,
select pH+ORP and then select ORP in [Measurement].
pH + ORP: Both pH and ORP are measured simultaneously. This setup also allows rH to be
measured. ORP measurement is based on a reference electrode
Table 16.2 Selecting sensor types
Sensor type Measurement (Sec. 16.2.1) Description
pH + ORP
pH
ORP For the ORP measurement on the basis of
a reference electrode
pH + ORP
pH + rH
rH
pH (not displayed) Same of pH of “pH + ORP”
ORP (not displayed)
For the ORP measurement on the basis of
a glass electrode
NOTE
The default of [Sensor type] is pH+ORP. Change this setting for your sensors. Not all sensor
types are available for some SENCOM sensors. For example, pH cannot be selected when an
ORP sensor is connected.
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 16.4.) Without temperature input, a temperature shown on the Main
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 16.7.)
Setting the Safe sensor disconnection to “Enable” allows operators to disconnect sensors. The
default is “Disable.”
When this setting is “Disable,” the safe sensor disconnection is not guaranteed because sensors
are performing measurement or automatic update parameters are being updated.
When this setting is “Enable,” sensors are not performing measurement or automatic update
parameters are not being updated, thus sensors can be disconnected safely.
16
SENCOM