Process Analytics: Measuring pH, Dissolved Oxygen, and Conductivity

pH, dissolved oxygen, and conductivity are important parameters to measure in industrial processes because they can provide valuable information about the products' quality and safety. By measuring these parameters, industrial processes can ensure that they are operating within safe and optimal ranges, which can improve the quality and efficiency of the products.

pH

pH is a measure of the acidity or basicity of a solution, and it can significantly impact the behavior of chemicals in a process. 

There are several ways to measure pH in industrial processes, including using a pH meter, pH test strips, and indicator solutions. A pH meter is a commonly used instrument that measures the pH of a solution by using a probe to measure the electrical potential difference between the solution and a reference electrode. pH test strips are also commonly used in industrial processes, as they are quick and easy to use and provide a general indication of the pH of a solution. 

Dissolved Oxygen

Dissolved oxygen is vital because many industrial processes involve biological organisms that require oxygen to survive and function properly. 

There are several ways to measure dissolved oxygen in industrial processes, but some of the most common methods include the following:

• Electrochemical sensors: These sensors use an electrode to measure dissolved oxygen concentration in a solution.
• Optical sensors: These sensors use light to measure the amount of dissolved oxygen in a solution.
• Membrane-based sensors: These sensors use a thin membrane to separate the sample being measured from the oxygen-sensitive material, allowing for accurate dissolved oxygen levels.

Conductivity

Conductivity is a measure of the ability of a solution to conduct electricity. It can provide information about the concentration of ions in the solution, which can be helpful in various applications. 

Conductivity in industrial processes is typically measured using a conductivity meter. This device uses electrodes to pass an electrical current through a substance sample and measures the substance's resistance to the flow of electricity. The resistance converts into a conductivity reading, typically reported in units of siemens per meter (S/m).

It's worth noting that the most appropriate method for measuring dissolved oxygen, conductivity and pH in industrial processes will depend on the application's specific requirements. It's always a good idea to consult with an expert in the field to determine the best method for your particular needs.

METTLER TOLEDO provides analytical transmitters for a wide range of analytics, including pH/ORP, oxygen, dissolved carbon dioxide and conductivity or resistivity. These analytical transmitters are the component within a measurement system that communicates displayed measurements to a user or higher level control system.  METTLER TOLEDO high-performance analytical transmitters offer compatibility with traditional analog sensors and digital sensors with METTLER TOLEDO's Intelligent Sensor Management (ISM).

Discuss your process analytics requirements with professional, skilled expert engineers. Alliance Technical Sales is available to assist in the application and specification of sensors, transmitters, and controllers for any industrial process. Call them at 630-321-9646 or visit their website at https://alliancets.com.

Dissolved Oxygen Measurement for Craft Breweries

Oxygen is both friend and enemy to the brewer!

It gives yeast what it wants to breathe and survive during the fermentation process and then becomes your main antagonist after the yeast has done its job.

Any process or transfer where beer becomes exposed to oxygen post-fermentation is an opportunity for oxygen to cause staling, muting, and shelf-life reduction. One example is the packaging process. The added oxygen resulting from placing the beer in cans, kegs, or bottles can affect the final product's consistency and taste.

As a brewer, you want to concentrate on producing the best-tasting beer. Therefore, it is critical to know how oxygen affects the brewing process and how packaging can eventually impact your beer's taste. It will give you the trust you need to create award-winning flavors that customers will enjoy, no matter how long the beer sits on the shelf.

METTLER TOLEDO Process Analytics offers the most accurate and cost-effective solutions for measuring dissolved oxygen in brewing applications. These robust optical dissolved oxygen sensors are durable and require minimal maintenance.

For more information about METTLER TOLEDO Process Analytics products in Illinois, Indiana, Iowa, and Wisconsin call Alliance Technical Sales at 630-321-9646 or visit their website at https://alliancets.com.

New 2020 Mettler Toledo Process Analytics Catalog

Mettler Toledo Process Analytics, which includes the well-known Thornton and Ingold brands, has published their 2020 product catalog.

Ingold has a long track record of innovative high-quality solutions for demanding process analytics applications. Their products include systems for the measurement parameters of pH/ORP, dissolved oxygen (DO), dissolved CO2, conductivity and turbidity.

Thornton is the market leader in critical ultrapure and pure water analytics, where accuracy and reliability are essential. Their products include analytical instruments and sensors for the measurement of resistivity, conductivity, TOC, bioburden, pH, dissolved oxygen (DO), sodium, silica and ozone.

For more information, and to download the 2020 MT Process Analytics catalog, visit this Alliance Technical Sales webpage.

Alliance Technical Sales, Inc.
630-321-9646
https://alliancets.com

Validating Water Cycle pH Requirements Using Conductivity and Calculated pH

In thermal power plants, pH measurement and control in the water steam cycle are critical to minimizing corrosion. Cycle chemistry guidelines specifically target narrow pH ranges.

However, in high purity water and steam, there are not enough ions in the water to generate a pH response, causing the pH reading to be unstable. Fortunately, conductivity has a direct relationship with pH when the sample contains only pure water with the typical alkaline treatments, such as ammonia and amines. In fact, cycle chemistry in many plants relies primarily on the related specific conductivity values. However, correction for minor contaminants by measuring the cation conductivity of the sample is needed to provide accurate results. The specific and the cation conductivity values are used in an industry accepted calculation that provides the highest accurate conversion to pH. Under normal operating conditions, this calculation provides more accurate and reliable results than pH electrodes can provide, for two reasons:

1. Conductivity is linear, with concentration which provides much higher resolution than pH sensors all of which give nonlinear response to concentration.
2. Conductivity sensors can be directly calibrated with minimal introduction of error. 

All pH reference electrodes have a variable junction or diaphragm potential that can change between buffer calibration and process measurement, introducing some uncertainty to subsequent measurements.

This makes calculated pH based on conductivity significantly more accurate. However, with major contamination, such as when a condensate exchange polisher's resin is exhausted, and an acid leak occurs, the pH would drop below 7, which is outside the ideal range for using calculated pH and would generate errors. Thus, to avoid contamination, it is recommended that both traditional pH measurement, and calculated pH based on conductivity, be used for optimal pH control.

METTLER TOLEDO Thornton's M800 multi-parameter transmitter can provide traditional pH measurement, calculated pH, as well as specific and cation conductivity to ensure accurate and reliable pH control. The M800 even has a built-in alarm to alert you if the pH measurement deviates from the calculated pH measurement for extra security and peace of mind.

For more infomration about METTLER TOLEDO Process Analytics products, contact Alliance Technical Sales by calling 630-321-9646 or by visiting https://alliancets.com.

Learn How a pH Sensor Works

pH Sensor (Mettler)

The video below will provide you with a basic visual understanding of the design of pH sensors and the principles behind pH probe operation. Before viewing the video, here are some pH basics:

What is pH measurement?

pH (potential of hydrogen) is a figure used to express the acidity or alkalinity of a solution on a logarithmic scale. On this scale 7 is neutral; lower values are more acidic and higher values are more alkaline, with a maximum measurement of 14. In process applications, pH is generally measured with an inline pH probe, the most common being the glass combination electrode. Additionally, an inline pH probe generally requires a process adaption, cable and transmitter.

How does a pH probe work?

A typical combination pH probe is made up of two separate electrodes built into one, a pH sensing electrode, and a reference electrode. In the simplest terms, a pH sensing electrode uses a special pH sensing glass membrane. H+ ions permeate the membrane creating a charge. The potential between the two electrodes is the measurement of hydrogen ions in the solution, giving the measure of pH. For more details, download the free pH Theory Guide.

What is the difference between a pH probe, a pH sensor and a pH electrode?

Absolutely nothing! The three terms are used interchangeably in the industry. They can be used for probes that are used in-process or in laboratory measurement. You may also hear the term "pH meter". This can be used for a piece of laboratory equipment, or the term pH meter can also be used to mean the combination of an inline pH probe, cable and transmitter.

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630-321-9646

User-Friendly Handheld pH Meter for Process Measurement

The Pro2Go handheld pH meter delivers high levels
of accuracy and functionality for process measurement.
Image courtesy Mettler-Toledo Process Analytics

A wide range of user-friendly features for accurate measurement of pH and redox are integrated into a versatile rugged handheld instrument from Mettler Toledo. The Pro2Go is designed and well suited for single-handed operation, with its light weight, slim case and intuitive operation. The device features compatibility with a range of analog and Mettler Toledo's ISM sensors. The Pro2Go provides superior service for many industrial process operations. Extending its applicability are intuitively linked menus, a graphic LCD display and operation in 10 languages.

A data sheet, included below, provides more detail on the robust pH and redox measurement system. Measurement data can be accumulated in the field, with up to 2000 readings stored in the unit available for simple transfer via USB connection.

For more detailed information, contact the process measurement specialists at Alliance Technical Sales. Share your process measurement challenges of all types with application specialists, leveraging your own knowledge and experience with their product application expertise to develop the most effective solutions.

Portable pH Meter for Process Measurement from Alliance Technical Sales, Inc.

New Portable pH and ORP Measurement Instrument

The Pro2Go portable pH meter provides top flight
measurement capability in a handheld portable package.
Image courtesy Mettler Toledo

Mettler Toledo has combined a broad range of user-friendly features in an industrially rugged, versatile, accurate instrument for pH and redox measurements. The Pro2Go is light weight and designed for single-handed operation. With compatibility among analog and Mettler Toledo's ISM sensors, along with a graphic LCD display and intuitive menu operation in 10 languages, the unit will provide superior service throughout many industrial process operations.

A data sheet, included below, provides more detail on the robust pH and redox measurement system. Measurement data can be accumulated in the field, with up to 2000 readings stored in the unit available for simple transfer via USB connection.

For more detailed information, contact the process measurement specialists at Alliance Technical Sales. Share your process measurement challenges of all types with application specialists, leveraging your own knowledge and experience with their product application expertise to develop the most effective solutions.

Portable pH Meter for Process Measurement from Alliance Technical Sales, Inc.

Process Analytics Product Guide

Ingold and Thornton brands provide wide ranging solutions
for process analytic challenges.
Image courtesy Mettler Toledo

Mettler Toledo is well known and regarded in the field of process analytical instrumentation. The company's line of sensors, transmitters, and analyzers delivers solid performance along with ease of use and reduced maintenance.

The full range of the company's Ingold and Thornton brand capabilities and applications for liquid, gas, and pure water analytics is illustrated in a newly available brochure. The document is useful as an overview of all potential intersections of your own work and the products and capabilities of Mettler Toledo.

Request a full copy of the brochure from a fluid analytics specialist. Share your measurement and analytical challenges with experienced professionals, leveraging your own process knowledge and experience with their product application expertise to develop effective solutions.

Mettler Toledo Process Analytics Product Guide from Alliance Technical Sales, Inc.

Automatic pH Sensor Cleaning and Calibration Saves Time and Cost

Automated pH sensor cleaning and calibration
with EasyClean 400
Courtesy Mettler Toledo

Measurement of pH is a common analytical operation in liquid processing. Whether chemical or wastewater operations, pH measurement provides useful information about process condition.

The sensors used for measuring pH can require care and maintenance, in the form of cleaning and calibration, to maintain peak performance. Traditionally, these operations have been performed manually by trained technicians. The task, though, is a good candidate for automation to provide cost savings and uniformity for sensor cleaning and calibration.

Mettler Toledo manufacturers four different automated cleaning and calibration systems for their analytical sensors. The offering ranges from simple water rinsing or compressed air cleaning to prevent build up to fully automated cleaning and calibration systems requiring little in the way of human intervention.

The technical data sheet below provides details about the fully automated system. Share your analytical measurement challenges and requirements with application specialists, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Automated pH Sensor Cleaning and Calibration from Alliance Technical Sales, Inc.

Retractable Sensor Housing for Analytical Sensors

The retractable sensor housings are available in several configurations

Process analytical sensors generally require some "care and feeding" to maintain specified performance levels. This maintenance can require removal of the sensor from the process in which it is inserted. Clearly, it is seldom advantageous to shut down a process for maintenance when it could otherwise remain in operation. The challenge - how to service the pH, redox, conductivity, or dissolved oxygen sensors without process interruption.

Mettler Toledo, under their Ingold brand of process analytic products, provides a solution in the form of a retractable sensor housing. Models accommodate sensors for pH, redox, conductivity, and dissolved oxygen. The housings are designed to enable safe retraction of the sensor from the process, with in place sensor cleaning or further maintenance operations made simple with the process remaining in operation.

The document below provides additional detail. Share your process analytical challenges with an application expert, combining your own process experience and knowledge with their product application expertise to develop effective solutions.

Retractable Sensor Housings for Analytical Sensors from Alliance Technical Sales, Inc.

Sensor Mount Transmitter Delivers New Functionality to Smart Sensors

The new M100 Sensor Mount Transmitter affixes directly
to ISM type sensors.

Smart sensors for pH, DO, and CO2 deliver a high level of performance and productivity enhancement for analytical users. Reduction in the time needed for sensor maintenance and calibration channel more time into delivering analytical results.

The new M100 SM (Sensor Mount) transmitter from Mettler Toledo streamlines the integration of their ISM smart sensors into bioprocess control systems. The transmitter mounts directly to the sensor, without the need for separately housed electronics. The compact configuration combines the advantages of the ISM smart sensor with several analog and digital outputs for connection to bioprocess controllers.

The M100 SM is available for use with  a variety of Mettler Toledo ISM sensors, including those for pH, DO, and CO2. The transmitters provide two 4-20 mA outputs and one digital Modbus RTU connection. Configuration and sensor status check can be accomplished via Bluetooth using a desktop PC or mobile device.

More detail is provided below. Share all your analytical challenges with application specialists, combining your own process knowledge and experience with their product application expertise to develop effective solutions.

Sensor Mount Transmitters For Smart Sensors from Alliance Technical Sales, Inc.

Intelligent Management for Process Sensors

Process analytical sensors can require scrupulous levels of attention and maintenance to continually deliver optimum performance. In some cases, overly frequent or involved maintenance is performed in order to avoid problems. Mettler Toledo, globally recognized leader in the development of process analytical sensors, developed a solution to streamline sensor maintenance and maximize reliability and performance.

The iSense software suite supports Mettler Toledo's line of intelligent sensors, monitoring and documenting sensor performance while maintaining real time indications of time to maintenance and calibration. Essentially, the iSense software provides guided sensor maintenance and continually verifies the operational health of the sensor to assure that delivered data is accurate and reliable.

There is much more to learn about how the iSense software and comprehensive offering of intelligent sensors can enhance process performance, as well as the efficiency of analytical operations. Reach out to a process analytics specialist with your analytical measurement challenges. Combining your process knowledge and experience with their product application expertise will yield an effective solution.