The FLXA21 is 2-wire module-type liquid analyzer that can be connected to up to two detectors from pH /ORP meters, conductivity meters, inductive conductivity meters, and dissolved oxygen meters.
By connecting two detectors of the same type, a more reliable system can be constructed as a high-precision duplex system.
And the impedance, asymmetric potential, slope, etc. of the detector are constantly measured, and continuously diagnostics status such as the electrode is dirty, damaged, broken and low measurement liquid level.
This self-diagnosis function of the detector reduces maintenace costs and improve OPEX.
OpreX is the comprehensive brand for Yokogawa’s industrial automation (IA) and control business and stands for excellence in the related technology and solutions. It consists of categories and families under each category. This product belongs to the OpreX Analyzers family that is aligned under the OpreX Measurement category.
| Area Classification | General Purpose Class I Div II (without the use of IS Barrier) Class I Div I (with the use of IS Barrier) |
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| Enclosure Material | Plastic (Polycarbonate) |
| Housing Rating | IP66/ NEMA 4A/ CSA 3S |
| Power Supply | 2-wire 24 VDC Loop Powered |
| Output Signal | Bi-directional HART digital communication, superimposed on mA (4-20 mA) signal Optional FF (FOUNDATION Fieldbus) and PF (Profibus) communication |
| Intrinsically safe type | ATEX, IECEx, FM, CSA and NEPSI, and nonincendive of FM and CSA. |
Built-in calibration standard table, with temperature compensation function and stability check function, realizes high-precision pH measurement.
In addition to pH measurements, temperature and redox potential (ORP) can also be measured.
As a diagnostic function of the detector, impedance, asymmetric potential, slope, etc. are constantly measured to continuously diagnose the state of the detector such as dirt/damage of the electrode, disconnection, and lowering of the measuring liquid level. In addition, the latest five calibration results are stored to predict future maintenance and calibration timing.

| Input Range | pH: -2 to 16 pH (with option /K: 0 to 14 pH) ORP: -1500 to 1500 mV rH: 0 to 100 rH Temperature: Pt1000, Pt100, 6.8k, PTC10k, 3k Balco, PTC500: -30 to 140 ºC, NTC 8k55: -10 to 120 ºC |
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| Performance (The specifications are expressed with simulated inputs.) |
pH | Linearity: ±0.01 pH, Repeatability: ±0.01 pH, Accuracy: ±0.01 pH |
| ORP | Linearity: ±1 mV, Repeatability: ±1 mV, Accuracy: ±1 mV | |
| Temperature | with Pt1000, PTC500, 6.8k, PTC10k, NTC 8k55, 3k Balco Linearity: ±0.3 ºC, Repeatability: ±0.1 ºC, Accuracy: ±0.3 ºC |
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| with Pt100 Linearity: ±0.4 ºC, Repeatability: ±0.1 ºC, Accuracy: ±0.4 ºC |
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| Performance (When combined with a pH detector) |
Repeatability | ±0.05 pH |
| Responsiveness | 10 seconds (90% response time, temperature-equilibrium pH detector at 20 ºC and standard solution, well agitated) | |
| Accuracy | ± 0.1 pH (when using PH8EFP, PH8EHP) ± 0.15 pH (when using our standard detector other than the above) |
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Built-in temperature compensation function and calibration standard table enable monitoring of the contamination of the cell for higher accuracy conductivity measurement.
Highly versatile, cell constants from 0.005 to 50 cm-1, two-way and four-way detectors are available.
It also supports five types of temperature detectors for accurate temperature compensation.
Performs pure water compensation in the analysis of demineralized water, steam, condensate, and boiler water. For monitoring of pure water in the pharmaceutical industry, the process liquid quality can be monitored according to the water quality standards of the USP item <645> (refer to item 645 of USP23 Article) guidance (USP).

| Input Specification | Two or four electrodes measurement with square wave excitation, using max 60m (200ft) cable (WU40/WF10) and cell constants from 0.005 to 50.0 cm-1 | |
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| Display range | Conductivity | min. 0.01 µS/cm, max. 2000 mS/cm (max 90% zero suppression) |
| Resistivity | min. 0.001 kΩ x cm, max. 1000 MΩ x cm (max 90% zero suppression) | |
| Temperature | min. span 25 ºC, max. span 270 ºC | |
| Performance (Accuracy) (The specifications are expressed with simulated inputs.) |
Conductivity | 2 µS x K cm-1 to 200 mS x K cm-1: Accuracy: ±0.5%F.S. 1 µS x K cm-1 to 2 µS x K cm-1: Accuracy: ±1%F.S. |
| Resistivity | 0.005kΩ / K cm-1 to 0.5MΩ /K cm-1: Accuracy: ±0.5%F.S. 0.5MΩ / K cm-1 to 1MΩ /K cm-1: Accuracy: ±1%F.S. |
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| Temperature | with Pt1000, Pb36, Ni100: Accuracy: ±0.3 ºC with Pt100, NTC 8k55: Accuracy: ±0.4 ºC |
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| Temperature compensation | NaCl table: ±1 % Matrix: ±3 % |
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| Temperature | 90 % (< 2 decades) in 7 seconds | |
For non-contact measurements based on the principle of electromagnetic induction measurement, it can be used for conductivity measurements in a wide range of applications, from acid and alkaline solutions to salt-containing solutions, as level monitoring in the chemical industry, such as the food and chemical industries, the plating and surface treatment industries, and the paper and pulp industries. It also has a matrix compensation and output linearization function to accurately analyze solutions of strong acid and strong alkali. Only one sensor can be connected.

| Input Specification | Compatible with the Yokogawa inductive conductivity ISC40 series with integrated temperature sensor: NTC30k or Pt1000. | |
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| Input Range | Conductivity | 0 to 2000 mS/cm at 25 ºC reference temperature. |
| Temperature | -20 to 140 ºC | |
| Cable length | max. 60 meters total length of fixed sensor cable + WF10(J) extension cable. Influence of cable can be adjusted by doing an AIR CAL with the cable connected to a dry cell. |
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| Performance (The specifications are expressed with simulated inputs.) |
Conductivity | Linearity: ±(0.4 %F.S. + 0.3 µS/cm) Repeatability: ±(0.4 %F.S. + 0.3 µS/cm) |
| Temperature | ±0.3 ºC | |
| Step response | 90 % (< 2 decades) in 8 seconds | |
This process analyzer achieves high functionality, high reliability, and reduced maintenance. Suitable for on-site installation and can be used under severe environmental conditions.
Not only galvanic sensors but also polarographic detectors can be used.
There are mg/L, ppm and % saturation units as the units for displaying dissolved oxygen concentration. In addition, for the best measurement accuracy, corrections are made for variations in atmospheric pressure, salinity in water, and temperature that differ depending on the altitude, etc.

| Input Specification | The FLXA202 accepts output from membrane covered Dissolved Oxygen sensors. These sensors can be Galvanic type, where the sensor generates its own driving voltage or Polarographic type, where the sensor uses external driving voltage from the converter. The input range is 0 to 50 µA for Galvanic sensors and 0 to 1 µA for Polarographic sensors. For temperature compensation, the FLXA202 accepts Pt1000 (DO30 sensor) and NTC22k elements (OXYFERM and OXYGOLD sensors). |
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| Measurement Range | DO Sensors | Dissolved Oxygen: 0 to 50 mg/l (ppm) Temperature: -20 to 150 ºC |
| DO30G | Measurement range: 0 to 20 mg/l (ppm) Temperature: 0 to 40 ºC |
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| Performance (Accuracy) (Performance in ppm mode) |
Linearity | ±0.05 ppm or ±0.8% F.S., whichever is greater |
| Repeatability | ±0.05 ppm or ±0.8% F.S., whichever is greater | |
| Accuracy | ±0.05 ppm or ±0.8% F.S., whichever is greater | |
| Temperature | Linearity: ±0.3 ºC Repeatability: ±0.1 ºC Accuracy: ±0.3 ºC |
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