pH and ORP Analyzers

what-is-ph-orpObtaining accurate pH and ORP measurements from your analyzer and interpreting this data correctly is critical to ensuring product quality and making accurate predictions of sensor lifetime.

Yokogawa’s pH and ORP measurement solutions include 2-wire and 4-wire analyzers featuring real-time online sensor diagnostics to provide reliable results. Our pH and ORP analyzers use the latest analyzer sensor technology to improve predictive maintenance and reduce the time and costs associated with sensor maintenance and replacement, optimizing your OPEX.

 

 

  FLXA402 FLXA202/FLXA21
 

Area Classification General Purpose
Class I Div II
General Purpose
Class I Div I
Class I Div II
Power Supply 110VAC, 24VDC
(4-wire)
24VDC loop-powered
(2-wire)
Communication 4-20mA, HART, Modbus
(Ethernet, RS-485), Bluetooth
4-20mA, HART, FF and PA*
Contacts and Relays 4 SPDT relays None

*FF (FOUNDATION Fieldbus) and PA (Profibus) communication only available in FLXA21

  • 2-Wire Transmitter/Analyzer FLXA202

    The FLEXA™ series analyzers are used for continuous on-line measurements in industrial installations. With an option for single or dual sensor measurement, they are the most flexible two-wire analyzer available.

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  • 2-Wire Transmitter/Analyzer FLXA21

    The FLEXA™ series analyzers are used for continuous on-line measurements in industrial installations. With an option for single or dual sensor measurement, they are the most flexible two-wire analyzer available.

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  • Personal Handheld Meter PH71/PH72

    The PH71/PH72 pH and/or ORP meter is a Compact, Easy-to-use, Drip proof – Ideal for Field Use. Features "One-Touch Calibration" and Temperature Compensation. Laboratory-Grade Intelligent pH Meters – Sized and Priced to Fit in Your Pocket

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Details

Optimize and eliminate surprise field maintenance, calibration and system configuration by utilizing real-time sensor diagnostic and predictive maintenance features built into Yokogawa pH and ORP analyzers.

Pure Water and Ultrapure Water

Purified water has very low conductivity, which means it is high in resistance because all the conductive components have been removed. In low conductive solutions combined with its susceptibility to contamination and temperature effects, makes accurate pH measurement very difficult. Pure water and ultrapure water is used in a variety of industrial processes such as semiconductor, power, water and pharmaceutical industries.

Achieving accurate and reliable readings using a traditional pH analyzer is challenging, however with the right equipment stable and accurate pure water pH measurements can be accomplished. 

Water and Wastewater

Water quality is crucial in all areas of life to process industrial automation. Applications such as aquaculture and chromium wastewater treatment rely on accurate pH and ORP measurements to ensure safe pH levels or proper control of chromium reduction processes.

Yokogawa's 4-wire and 2-wire pH analyzer solutions with suitable immersion fitting and sensors are ideal for measuring these crucial pH and ORP measurements.

Pulp and Paper

The demanding applications and severe process conditions in pulp mills pose challenges for accurate, repeatable and reliable liquid analysis measurements. Treating wastewater from pulp and paper plants requires maintaining proper pH levels, which can be controlled by referring to a pH analyzer.

Yokogawa pH and ORP analyzers include real-time sensor diagnostic and predictive maintenance features to continuously and stably measure pH levels, eliminate the need for frequent manual cleaning, and enable efficient use of flocculating agents.

Chemical

The chemical industry presents multiple challenges such as chemical attacks, maintenance, safety, consistency and reliability to any liquid analysis measurement. In flue gas desulfurization systems that use magnesium hydroxide (Mg(OH)2 ) slurry, the consumption of the desulfurization agent (Mg(OH)2 ) is controlled using online pH analyzers.

Yokogawa’s pH measurement solutions ensure stable, continuous pH measurement over long periods, reduce operating costs, and eliminate manual cleaning.

Resources

Overview:

Yokogawa & Nouryon Co-Innovation Leads to New PH-Analyzer
 
 

Industries:
Application Note
Overview:

The term "cooling tower" is used to describe both direct (open circuit) and indirect (closed circuit) heat rejection equipment. Cooling towers are heat-transfer units, used to remove heat from any water-cooled system. The cooled water is then re-circulated (and thus, recycled) back into the system. Since the process water is re-circulated, the mineral concentration increases as a result of the evaporation. (AN10B01B20-01E)

Industry:Refining, Food and Beverage, Power, Oil and Gas, Pulp and Paper, Chemical

Industries:
Overview:

Measurement of pH in high purity water presents many difficulties. Yokogawa's pH instrument's design success comes from addressing the unique challenges of the application.

Overview:

Dairy wastewater is a mixture of organic compounds, suspended solids, fats, and bacteria that can produce a film or coating on equipment in the process. 

Overview:

There are many points in the processing of edible fats and oils that benefit from the use of analytical measurements. Inductive conductivity, contacting conductivity, gas density, and pH can be utilized to increase the quality of the end product, as well as protecting expensive processes.

Overview:

Control of sodium chloride (NaCl) concentration at a salt dissolver where solid salt is dissolved in water, is highly important because of the electrolysis efficiency. A conventional way of measuring the concentration of supersaturated NaCl solution had been performed by using non-contact type sensors (e.g., γ-ray density meter) since NaCl, impurities, and precipitates are in the solution.

Overview:

Most zinc are produced at hydrometallurgically, where a high-grade zinc product can be obtained and valuable metals mixed in the raw material can be recovered. In the hydrometallurgy, the raw material of zinc concentrate is roasted and then dissolved in sulfuric acid to remove impurities. The process called leaching and pH control of the leachate is important.

Industry:Chemical, Power

Industries:
Overview:

The control of the world's water resource is arguably one of the most important issues. Water demand from industry and domestic users is set to rise throughout the industrialized world. Yokogawa has been applying minimized maintenance measurement systems.

Overview:

Clean-in-place (CIP) is the system designed for automatic cleaning and disinfecting in the food & beverage, pharmaceutical, and chemical industries. Tanks and piping are cleaned and sterilized with various cleaning solutions, fresh or hot water, or steam after manufacturing products is completed.

Overview:

Problems at the wet end of a paper machine can rarely be corrected downstream. That is why monitoring and controlling pH in pulp stock is critical to the paper-making process. Essentially, at every stage in the manufacture of paper, correct pH values play a vital role. Variations in the pH value at the headbox have a negative effect on the quality of the paper produced. Proper monitoring ensures minimizing plugging and fouling problems that occur with pH measurements in paper mills. 

Industries:
Overview:

Cyanide-bearing wastewater from mining and electroplating facilities and certain types of chemical plants is toxic and must be treated by oxidation with chlorine or chloride to bring the cyanide concentration within regulatory limits.

Industry:Electrical and Electronics

Overview:

The treatment of wastewater from pulp and paper plants is a serious environmental concern. Yokogawa's submersion holder with an ultrasonic+air-jet cleaner (customized product) can reduce the manual cleaning frequency to just once every one or two months.

Industries:
Overview:

Continuous technology improvement is ongoing in the pulp & paper industry to obtain the best possible performance. Problems at the wet end (stock preparation) can rarely be corrected downstream. That is why monitoring and controlling pH in pulp stock is critical to the paper making process. Essentially, at every stage in the manufacture of paper, correct pH values play a vital role.

Overview:

Reverse osmosis (RO) is a separation process that uses pressure to force a solution through a membrane that retains the solute on one side and allows the pure solvent to pass to the other side. More formally, it is the process of forcing a solvent from a region of high solute concentration through a membrane to a region of low solute concentration by applying a pressure in excess of the osmotic pressure.

Overview:

Sour Water is the wastewater that is produced from atmospheric and vacuum crude columns at refineries. Hydrogen sulfide and ammonia are typical components in sour water that need to be removed before the water can be reused elsewhere in the plant. Removal of these components is done by sending the sour water from the process to a stripping tower where heat, in the form of steam, is applied.

Overview:

Power plant boiler houses designed to burn coal or high sulfur oil are required by Federal and State pollution regulations to "scrub" (remove) sulfur dioxide from flue gasses to meet emission limits. SO2 in flue gasses is known to be harmful to the environment, as it is one contributor to the formation of acid rain. pH control is critical for the proper functioning of the scrubber system.

Industries:
Application Note
Overview:

For control of batch neutralization, a pH measurement coupled with a timer-controlled chemical feed scheme provides very satisfactory results.

This system can be adapted for either acid waste or alkaline waste neutralization.

Application Note
Application Note
Overview:

Wastes have been considered to be a serious worldwide environmental problem in recent years. Because of increasing pollution, these wastes should be treated. However, industrial wastes can contain a number of valuable organic components. Recovery of these components is important economically. Using conventional distillation techniques, the separation of acetic acid and water is both impractical and uneconomical, because it often requires large number of trays and a high reflux ratio. In practice special techniques are used depending on the concentration of acetic acid. 

Industries:
Application Note
Industries:
Application Note
Application Note
Overview:

In flue gas desulfurization systems that use magnesium hydroxide (Mg(OH)2) slurry, the consumption of the desulfurization agent (Mg(OH)2) is controlled by using online pH analyzers. A great concern in the pH measurement is heavy staining of the pH electrodes by the Mg(OH)2 slurry. To ensure accurate measurement, frequent cleaning of the electrodes with an acid is required, adding to both maintenance workload and cost.

Industry:Chemical, Power

Overview:

In stable dispersion of fine particles is the pre-requisite for the selective flocculation technique involving separation of ultra-fine valuable particles from the gangue. Among mineral processing techniques selective flocculation technique is known to have outstanding potential of capturing the particles of particular mineral in slurry of mixed mineral system by selective adsorption of water soluble polymers known as flocculants.

Application Note
Overview:

Where and why are the pH Measurements important in a brewery? No one wants a skunky beer. pH measurements in the wort, during mashing/souring the malt, and in the yeast enzymes are critical.
 

Industries:
Overview:

After extraction from sugar cane or sugar beets, the juice must be purified to remove the many other organics and minerals that accompany it. The processing to accomplish this is heavily dependent on reliable pH measurement and control as illustrated. 

Overview:

The quality of paper for printing or writing should be high and it depends on many parameters. Cobb is one of the parameters, which requires control. Using a retractable fitting, this optimum pH level can be achieved by using Yokogawa's 4-wire pH Analyzer with a suitable, retractable fitting and sensor. Since a separate controller is not required for the dosing pump, this solution provides a cost-saving.
 

Industries:
Overview:

Wastewater from electroplating facilities and certain types of chemical plants contains toxic forms of hexavalent chromium such as chromate and dichromate. The hexavalent chromium in this wastewater must be reduced before the water can be discharged. This requires a two-step process: hexavalent chromium (CR6) is reduced to trivalent chromium (CR3); and CR3 is precipitated as chromium hydroxide.

Industry:Electrical and Electronics

Overview:

 

 

Application Note
Overview:

Fish are totally dependent upon water to breathe, feed, grow, maintain a salt balance, and reproduce. Water quality determines the success or failure of an aquaculture operation.

Application Note
Overview:

In the manufacturing of Glass-Fiber wool for insulation a melt of a material such as glass is inductively heated at a stage intermediate an initial liquefying stage and a refining stage. Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, where eddy currents are generated within the metal and resistance leads to Joule heating of the metal.

Application Note
Overview:

The level of dissolved oxygen is critical to the quality and consistency of any brew. Too little dissolved oxygen results in the fermentation step of the process will lead to: off flavors (e.g. poor removal of diacetyl and acetaldehyde), poor yeast crop in terms of quantity and vitality, and low ester and alcohol production. 

Overview:

The detectors used to perform dissolved oxygen (DO) measurement in oxidation ditch type sewage treatment plants tend to become dirty quickly and require frequent cleaning. It has been d ifficult to remedy this problem inexpensively. One solution that significantly reduces the sensor maintenance workload is the use of float holders.

Industries:
Overview:

Many Ethanol plants running today are using a combination style pH electrode with a non-flowing reference to measure pH in the Mash Slurry transfer line from the Mash slurry mix tank to cook. The Mash is being pumped out of the Mash Slurry tank is at approximately 180 °F and 40 to 60 psig.

Overview:

Yokogawa’s conductivity transmitters and converters possess USP functions that make this seemingly complex and troublesome requirement pain-free and automatic.

Overview:

The lifetime of a pH sensor has a significant impact on the overall annual costs of a pH measuring loop. Optimizing four key factors will decrease these costs and optimize process control and overall plant efficiency.

Media Publication
Successful pH Troubleshooting
(TN-P-20210201-01)
Edition 1
Overview:

The accuracy of pH measurements depends upon maintenance; maintenance frequency largely depends upon the application. Understanding and addressing the causes of pH measurement difficulties comprise key to ensuring stable and accurate readings.

Industries:
The input module you need depends on the Model Number of your FLXA Analyzer.
Overview:

The input module you need depends on the Model Number of your FLXA Analyzer.

PH150 Forgot Password?
(KB-000-0209)
The PH150 allows the use of passwords to limit access to the Calibration functions and access to the Configuration functions. If these functions have been protected with a password and the password is not available there is a way to bypass the prote...
Error 130 & 131 are display errors. The PH450 calibrates the display each time it powers up. Error 130 or 131 means this calibration failed. Cycle the power to the unit and allow it to calibrate the display again. If after 6 times the error is st...
Why is pH Calibration important? How to clean pH glass? Which pH buffers should I use?  How fresh should pH buffer solution be?  How long between calibrations?
Edition 1
Overview:

Why is pH Calibration important? How to clean pH glass? Which pH buffers should I use?  How fresh should pH buffer solution be?  How long between calibrations?

An Error 2 means that the calculated asymmetry potential is outside the acceptable range. The Asymmetry Potential (AS), also referred to as the millivolt offset, is an indication of the condition of the reference electrode. Theoretically when the ele...
The current termination of sales date for the EXA450G series is estimated to be around April of 2020. As the date gets closer announcements will be made. Following Yokogawa's normal practice, all spare parts will still be available for five ...
The Error 3 is related to the slope value on a pH loop, indicating that the slope value is outside of the allowable range. The Slope (SL), also referred to as the efficiency of the electrode, is an indication of the condition of the pH electrode. The...
Air bubbles are normal in pH sensors and in some reference sensors. They are necessary because the pH sensor is a sealed device with no vent. Without the air bubbles the expansion and contraction of the liquid with temperature changes could cause the...
Yes. The Cation Differential pH and ORP sensors have a glass electrode that needs a 2 point calibration performed regularly. Because of the Cation Reverence electrode you must use special buffers with a constant sodium ion concent...
A tiny crack in the membrane of a glass electrode is not always visible to the naked eye. Frequent shocks may create cracks in the glass that cause measurment errors. These cracks will cause the analyzer to read 0 mV and the ...
It is very important that the cables maintain a very high impedance. If any moisture penetrates the cable the impedance will drop and the cable will short out the voltage generated by the pH sensors. This will cause errors or a total loss of mea...
Often, Instrumentation technicians like to shorten cables to match the installation. This is strongly discouraged with Analytical Sensors. Yokogawa has designed cables with a special layer of conductive plastic to ensure maximum noise ...
We recommend using pH buffers only once. If you want to use the same buffers for more analyzers, then you must avoid contamination of the buffers by the sensors. The sensor must be cleaned and washed carefully before inserted into the buffer. A senso...
That is possible but not guaranteed. The 225 mm sensor body is longer, so it has more electrolyte. Often the reference electrode fails because the electrolyte is depleted as it diffuses through the reference junction into the process. With ...
Most pH sensors with a glass membrane cannot be mounted upside down. To absorb the thermal expansion of the internal buffer solution there is always a sizeable air bubble inside the sensor. When the sensor is mounted upside down the reference element...
Yokogawa offers the PH18 sensor. This sensor is nonglass and suitable for regular CIP and SIP cycles.
In a dual input FLXA202 or FLXA21 analyzer you can use a HART Splitter to convert the HART® dynamic variables into current outputs or contact outputs. The model number is "1W-KFD2-HLC-EX1.D" and the description is "P+F HART Splitte...
Yokogawa's pH and conductivity sensors include a temperature sensor to allow for temperature compensation. The pH and conductivity sensors have a relatively large temperature mass and respond slowly to the changes in the process temperature. This...
Generally we state that the pH analyzer is as accurate as the care that is given to the device allows. With lots of care you can achieve 0.05 pH accuracy. With normal care you achieve 0.1 pH Without care the measuring error can be pH 0.5 or more...
The PH150 and SC150 were discontinued in 2004. The Manual and General Specification sheet are no longer available on Yokogawa's website. Use this link to download a zip file containing both documents.
The TM20 pH meter was discontinued over 20 years ago, but the manual is still available.  If you have trouble downloading it, send us an email at support@us.yokogawa.com or call 800-524-7378.
First, check the grounding. A bad ground can cause this failure.  Next: cycle the power to the unit. Shut the power off for 30 seconds then restart.  If that doesn’t clear the error reset the analyzer to factory defaults. Be ...
Performing a two point calibration for an ORP sensor may make a user more confident in the measurement because it ties the measurement to two known millivolt values, offsets and slope values. When performing a pH calibration, the 2nd point&...
Yes, the input module can be changed in the Converter.    See the FAQ: Which Input Module do I order for my FLXA21/202 analyzer? ...
The reference potential difference between 1 molar and 3.3 molar is approximately 30 mV. The sensitivity of a pH sensor at reference temperature is 59mV/pH. So if you combine a measuring cell filled with 3.3mol KCl with a reference cell with 1mol KCl...
Yokogawa's buffer solutions have a guaranteed shelf life of 12 months from the date of shipment. The exception to this is the sodium buffer solutions used to calibrate the differential pH sensors (part numbers K1520BF, K1520BG, K1520BH, K152...
All Yokogawa analyzers use an open architecture with adjustable temperature compensation, adjustable isopotential point, and adjustable slope. They are compatible with all direct pH, ORP, and conductivity sensors. There are two exceptions to th...

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Videos

Overview:

This video aims to answer the following: How does a traditional pH reference work and what are it's common problems? How does a sodium pH reference work and what are it's benefits? This webinar was presented February 12th, 2013.

Overview:

Watch this on-demand webinar to review and learn the theory behind pH measurement, the issues surrounding high purity pH measurements, and how to implement good calibration and maintenance procedures.

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