All-in-One pH/ORP Water Quality Sensor with Pt1000 Temperature Sensor and Solid

Product Specification

The FU20 and FU24 all-in-one sensors show how Yokogawa applies the motto "Simple is best" to sensor technology. These sensors feature four separate elements (pH, reference, temperature, ORP) allowing for simultaneous measurement of pH and ORP is possible with one sensor in a rugged Ryton or PVDF (FU20) and Ryton (FU24). The integral or variopin cable comes number-coded cable along with the integral NPT threads on the sensor makes installation convenient. The Quick Release Adapters for the FU20 allow easy removal of the sensor for cleaning and calibration.

Features and Benefits

• Available as analog and digital SMART sensors (SENCOM)
• Solid Platinum ORP/LE electrode for accurate simultaneous pH and ORP measurements.
• Integral Pt1000 element for accurate temperature measurements and enhanced pH accuracy
• Double junction and long diffusional path for reference pollution/poisoning resistance
• Saturated Ag/AgCl reference system with double junction combined with polymerized saturated KCl and ion-trap prolong the life of the reference probe even in chemically unfavorable environments.
• Extended life time by large volume of polymerized electrolyte and porous PTFE diaphragm
• Cation Differential reference system available in the FU20 for elongated life
• Variopin connector or integrated cable options
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• Versatile Direct in-line, immersion, off-line installation (flow fitting) and retractable Hot-tap (available with use of the FU20 only)
• Quick-Release adapter available for the FU20
• Calibration certificate delivered with each sensor
• Patented automatic pressure compensation in the FU24
• Available in two versions, a robust dome shape model for applications with a limited amount of solids, and a flat surface model for applications in which solids are a considerable component

The FU20 combination sensor shows how Yokogawa applies the motto "Simply the best" to sensor technology. The wide body sensors (26 mm diameter) hold four separate elements in one unbreakable PPS40GF (RytonTM) or PVDF body. Installation is simple with the integrated industrial 3/4" tapered thread. The large volume gelled electrolyte and the double junction reference system slows down depletion and poisoning therefore extending the lifetime. The system is targeted at those applications where simplicity will result in accurate and reliable pH- or redox measurements. This means that in 90% of the know applications this sensor will be an excellent choice.

The FU24 is an all-on-one pH and ORP sensor made with a chemical resistant PPS 40GF body for harsh pH applications. It is particularly useful in applications with fluctuating pressure and/or temperature. These processes shorten sensor life because the process fluids move in and out of the sensor under influence of frequent pressure and/or temperature fluctuations. This results in fast desalting and dilution of the reference electrolyte which in turn changes the reference voltage causing a drifting pH measurement.

By integrating the successful Yokogawa patented Bellow design concept within the FU24 electrode, a strong pressure compensation mechanism is created. The built-in bellow ensures immediate interior pressure equalization to the outside pressure, making the sensor virtually insensitive to external pressure variations. A slight overpressure caused by the bellow tension, prevents fluid ingress and maintains a positive ion flow out of the sensor.

FU20 Measuring elements

: pH glass electrode
: Silver/Silver chloride reference
: Solid platinum electrode
: Pt1000 temperature sensor.

Wetted parts

Sensor body    : PPS GF40    for type NPT, FSM
: PVDF GF20+TZ4 for type FTD
Earthing pin    : Solid Platinum
Measuring sensor    : G-glass
LE glass tube    : AR-glass
O-ring    : Viton
Reference junction    : Porous PTFE

Functional specifications (at 25 °C)
Isothermal point    : pH 7 / 3.3m KCl
Reference system    : Ag/AgCl with saturated KCI Glass impedance
-Dome shape    : 200 MΩ nominal
-Flat Surface    : 750 MΩ nominal Junction resistance    : < 10 kΩ
Liquid outlet    : non-flow double junction Temperature element    : Pt1000 to IEC 751 Asymmetry potential    : 8 ± 15 mV
Slope    : ≥ 96 % (of theoretical value)

Note: The temperature sensor included in the FU20 is designed for process compensation and for indication. It is NOT designed for process temperature control.

Dynamic specifications
Response time pH    : t90 < 15 sec. (for 7 to 4 pH step) Response time temperature
-Dome shape    : t90 < 1 min. (for 10 °C step)
-Flat surface    : t90 < 4 min. (for 10 °C step)
Stabilization time pH    : < 2 min. (for 0.02 pH deviation during 10 sec.)

Operating range
pH    : 0 to 14
ORP    : -1500 to +1500 mV
rH    : 0 to 100
Temperature
- Dome shape    : -10 to +105 ºC (14 to 221 ºF)
- Flat Surface    : +15 to +105 ºC (59 to 221 ºF)

Pressure    : Barg See Graph 1
: Barng 0 to 0.985 (0 to 14.36 psi) (under pressure)
Conductivity    : > 50 μS/cm

FU24 Measuring elements
: pH glass electrode
: Silver/Silver chloride reference
: Solid platinum electrode
: Pt1000 temperature sensor.

Wetted parts
Sensor body    : PPS 40GF
Earthing pin    : Solid Platinum
Measuring sensor    : G-glass
LE glass tube    : AR-glass
O-ring    : Viton
Reference junction    : Porous PTFE
Bellow system    : Viton
Functional specifications (at 25 °C)
Isothermal point    : pH 7 / 3.3M KCl
Reference system    : Ag/AgCl with saturated KCI Glass impedance
-Dome shape    : 200 MΩ nominal
-Flat Surface    : 750 MΩ nominal Junction resistance    : < 15 kΩ
Liquid outlet    : non-flow double junction Temperature element    : Pt1000 to IEC 751 Asymmetry potential    : 8 ± 15 mV
Slope    :  96 % (of theoretical value)

Note: The temperature sensor included in the FU24 is designed for process compen- sation and for indication. It is NOT designed for process temperature control.
Dynamic specifications
Response time pH    : t90 < 15 sec. (for 7 to 4 pH step)
Response time temperature
-Dome shape    : t90 < 1 min. (for 10 °C step)
-Flat surface    : t90 < 4 min. (for 10 °C step)
Stabilization time pH    : < 2 min. (for 0.02 pH deviation during 10 sec.)

Operating range
pH    : 0 to 14
ORP    : -1500 to +1500 mV
rH    : 0 to 100
Temperature
- Dome shape    : -10 to +105 ºC (14 to 221 ºF)
- Flat Surface    : +15 to +105 ºC (59 to 221 ºF) Pressure    : Barg See Graph 1
: Barng 0 to 0.990 (0 to 14.36 psi) (underpressure)
Conductivity    : > 10 μS/cm