Yokogawa FU20/PH20 All-in-One pH/ORP Sensor - Manual (Page 11)

IM 12B6J3-E-H
7
4. GENERAL SPECIFICATIONS FU20
4-1. Measuring elements : pH glass electrode
: Silver chloride reference
: Solid platinum electrode
: Pt1000 temperature sensor.
4-2. Construction materials
Body
: PPS 40GF (Ryton) with glass filling
Earthing pin : Solid Platinum
O-ring : None
Reference junction : Porous PTFE
Cable : Coaxial with 4 extra leads
4-3. Functional specifications (at 25°C)
Isothermal point
: pH 7
Glass impedance
- Dome shape : 250 to 500 M
Ω
- Flat Surface : 400 to 1000 M
Ω
Reference system : Ag/AgCl with saturated KCI
Junction resistance : 0.5 to 5 k
Ω
Temperature element : Pt1000 to IEC 751
Asymmetry potential : < 15 mV
Slope : > 96 % (of theoretical value)
NOTE:
The temperature sensor included in the FU20 is intended to provide indication and cell
compensation. The construction has not been tested to the pressure vessel standards
required for plant temperature control.
4-4. Dynamic specifications
Response time pH step (7 to 4)
: < 15 sec for 90%
Response time temp step (10°C)
- Dome shape : < 3 min for 90%
- Flat Surface : < 6 min for 90%
Stabilisation time (0.02 pH unit/ 10 s) : < 2 minutes
4-5. Operating range
pH
: 0 to 14
Temperature : -10 to 105 °C (14 to 221 °F)
Pressure : 0 to 10 bar ( 0 to 145 PSIG)
Conductivity : > 50 µS/cm
Storage temperature : -30 to 50 °C (-22 to 122 °F)
NOTE:
Specifications should not be considered in isolation. For example the pH range can be
2-12 pH, where the measurement is at elevated temperatures. For advice about specific
applications please contact you local sales office.