Manual

<1. Wiring and Installation>
3
IM 12A01A02-12E 4th Edition : Sep. 3, 2013-00
1.3 Wiring the sensor
The FLXA21 can be used with a wide range of commercially available sensor types, both from
Yokogawaandothermanufacturers.Formoredetailedinformation,refertotherespective
instructionmanualofthesensor.ThesensorsystemsfromYokogawafallintotwocategories;the
onesthatuseaxedcableandtheoneswithseparatecables.
Toconnectsensorswithxedcables,simplymatchtheterminalnumbersintheinstrument
withtheidenticationnumbersonthecableends.Theseparatesensorsandcablesarenot
numbered, but instead use a color-coding system.
1.3.1 pH Measurement
Conventional pH sensors are connected to the module as follows:
11 Temperature
12 Temperature
13 Reference
14 Solution ground
15 Glass (measure)
16 Shield
17 Shield
FLXA21
REFTC PHLiquid
Earth
In addition to the wiring of the sensor, insure that a jumper for low-impedance sensor inputs is
installed. The jumpers can be found on the plastic sensor module cover and can be stored in the
lower level module wiring cover.
• pHGlassElectrodeisahighimpedancesensorinput
• Specialelectrodesusing2glasssensor(example:Pfaudler,SC24V)donotneedjumpers.
Terminals15-16areidentiedasinput1(HighImpedance)andterminals13-17aredenedas
input 2 (Low Impedance). For conventional pH sensors, the jumper is placed as illustrated:
16
15191713181412
11
PH
Input 1
Input 2
Glass sensor on Input 1.
Reference sensor on Input 2.
Jumper
holder