Understanding PPM: A Guide to Water Treatment and Industrial Measurements

Table of Contents

Accurate dosage, monitoring, and control of the levels of various substances in water is critical to ensure the quality of water used in industrial settings. For industrial water treatment, PPM (parts per million) is an important measurement. 

Water treatment professionals, building owners and operators, and facility managers use PPM measurements to accurately monitor and control the levels of various substances in water. 

Knowing the PPM levels of the various impurities and water treatment chemicals used is important to ensure water quality and protect the boiler, chiller, closed loop, cooling tower and HVAC systems it flows through.

What is PPM (Parts per Million)?

PPM stands for “parts per million”. It is a unit of measurement that expresses the concentration of a substance in a mixture. PPM in water refers to the concentration of chemicals or impurities within the water. 

One part per million means that there is one unit of a substance for every million units of the mixture. This ratio helps to understand the dosages of chemicals required for effective water treatment. 

Why are PPM Measurements Important?

PPM (parts per million) measurements are used to determine the quantity of substances present in a process, system or environment. These measurements are used to maintain water quality, optimize water treatment, monitor industrial processes, and safeguard equipment and systems. By measuring PPM, you can identify problems, make solutions to keep people safe, and track concentrations over time. 

PPM in Water Treatment

 In water treatment, PPM determines the levels of contaminants, such as: 

  • Dissolved oxygen 
  • Chlorides 
  • Water hardness (calcium and magnesium) 
  • Trace metals 
  • Microorganisms 
  • Organic compounds 
  • Minerals, salts, and other contaminants 

Knowing the PPM level of contaminants of concern in your feed water helps you make informed decisions about the required chemical dosages to protect your boiler, chiller, closed loop, cooling tower and HVAC systems. 

It also helps identify any equipment issues. For example, if your system includes a water softener but water hardness is high, you know the softener may need repair. 

PPM measurements are often used to express the dosage rate of chemical water treatment solutions used to protect your system. Dosage rates or concentrations in your boiler, chiller, closed loop, cooling tower and HVAC systems are often defined in PPM. This includes the dosage rates for our AQUAGUARD series of industrial water treatment products.

PPM in Industrial Applications

Parts per million (PPM) measurement is widely used in numerous industrial applications for maintaining quality control and process efficiency across industries. Guardian Chemicals commonly uses PPM tests to determine the concentration of its products in processes and systems. Examples include determining cleaning agent concentrations and controlling treatment in rig boilers. 


Determining Soap Concentrations Using a Conductivity Meter: 

For best results, accurate measurement of cleaning agent concentrations such as NuTech Grand Slam are crucial for achieving optimal cleaning performance. A conductivity meter is a popular tool to measure soap concentrations in parts per million (PPM). The conductivity of the cleaning solution correlates to the cleaner dilution or concentration. Knowing the concentration allows you to find the right balance between effectiveness and cost-efficiency and ensure the right concentration to protect surfaces and people. 


Controlling Treatment in Rig Boilers: 

Rig boilers play a critical role in the oil and gas industry, providing heat and steam to various processes. PPM measurements are critical to determine acceptable rig boiler feed water, and proper EZE Treat treatment. By monitoring the pH and water hardness, operators can optimize their rig boilers and ensure proper water treatment. This maintains the boiler’s efficiency, prolongs its lifespan, and reduces maintenance costs. 


Monitoring Air Quality: 

Another vital application of PPM measurements is in monitoring air quality, particularly in industrial settings where hazardous gases may be present. Measuring gas concentrations in parts per million ensures that safety regulations are met, and workers are protected from potential health hazards.

PPM-based gas detection systems and portable monitors can detect various gases, including carbon monoxide, hydrogen sulfide (H2S), volatile organic compounds, and LELs providing real-time data to maintain a safe working environment. 

H2S and LEL testing are often used in turnarounds, shutdowns, tank and vessel cleaning operations to determine proper dosage of our SOURGUARD and PURGE series of products. These degassing agents make the working environment safer by removing H2S and LELs. 


Water Treatment and Purification: 

PPM measurement is used in water treatment and purification processes to monitor the concentration of contaminants, such as heavy metals and organic compounds. PPM-based systems ensure the water’s safety and compliance with regulations. In wastewater treatment plants, PPM measurements are essential for optimizing the treatment process and tracking the efficiency of contaminant removal.

Methods of Measuring PPM

There are several methods for measuring PPM in water treatment. The most common techniques used on site are: Colorimetry, Titration, and Electrochemical methods. These and other PPM measurements are defined below. 


Titration: To measure the amount of a specific substance in water, a reagent is added to the water sample. The amount of reagent needed to react with the substance is measured. Depending on the titration, the end point may be determined by a change in color, pH, or another measurable parameter. Many of Guardian Chemicals “drop test” water treatment test kits use titrations to determine concentration. Laboratory titrations are often performed using a burette for greater accuracy. 


Colorimetry: A reagent is added to the water sample that reacts with a specific component, producing a color change. The intensity of the color is measured using a colorimeter, and the PPM calculated based on color intensity. The HACH DR890 and DR900 portable colorimeters are commonly used for on-site testing of various water parameters.  


Spectrophotometry: Like colorimetry but uses a spectrophotometer to measure the intensity of light absorbed by the sample at a specific wavelength. This method is more accurate and precise than colorimetry. 


Electrochemical methods: Ion-specific electrodes measure the concentration of specific ions in water. Examples include conductivity meters for measuring total dissolved solids (TDS) or ion-selective electrodes for measuring specific ions like chloride or fluoride. Electrochemical tests commonly performed on site include pH and conductivity. 


Gravimetry: Evaporating a known volume of water sample and weighing the residue. This determines the total amount of dissolved solids, which can be converted to PPM. 


Mass spectrometry: This is a more advanced and expensive method that involves ionizing the water sample and analyzing the ions using a mass spectrometer to determine the composition and concentration of the dissolved solids. 

PPM Calculator

When converting units of measurement, it’s essential to understand the relationships between them. Some common conversions include: 

PPM to mg/L: Since 1 ppm is equal to 1 milligram per liter (mg/L), no conversion is necessary. 

PPM percentage: To convert from PPM to percent, divide the PPM value by 10,000. 

PPM to µg/L (micrograms per liter): Multiply the PPM value by 1,000. 

For example, if you have a concentration of 5 PPM, values are: 

5 mg/L 

0.0005% (5 / 10,000) 

5,000 µg/L (5 * 1,000) 

PPM Calculator Tool

PPM Calculator Tool

Maintaining Accuracy in PPM Measurements

Accurate PPM measurements are critical for effective water treatment. To ensure the reliability of your measurements: 

  • Use calibrated instruments: Calibrate and maintain your measuring equipment to ensure accurate readings. 
  • Follow proper sampling procedures: Collect water samples from representative locations and ensure they are well-mixed before analysis. 
  • Prevent sample contamination: Use clean, appropriate containers and avoid contaminating the sample with your hands. 
  • Perform duplicate measurements: Conducting more measurements and averaging the results can help identify and reduce errors. 
  • Install quality control measures: Use standard solutions and reference materials to verify the accuracy of your measurements. 
  • Keep detailed records: Document your procedures, equipment maintenance, and measurement results to track trends and identify potential issues. 


In conclusion, PPM (parts per million) is an essential measurement not only in water treatment but also in various industrial applications. It plays a pivotal role in maintaining water quality, optimizing process treatment, and safeguarding systems and equipment.

It’s important to understand PPM measurements and implement accurate test methods such as titration, colorimetry, and electrochemical techniques. These practices allow professionals in water treatment, and other industries to make informed decisions regarding chemical dosages, treatment effectiveness, and system maintenance. 

In addition to Water Treatment, PPM is used in applications to determine soap concentrations, control treatment in rig boilers, and monitor air quality. Maintaining the accuracy of PPM measurements is crucial in all applications, and can be achieved by calibrating instruments, following proper sampling procedures, preventing sample contamination, performing duplicate measurements, installing quality control measures, and keeping detailed records. 

With a thorough understanding of PPM and a commitment to ensuring accurate measurements, you can optimize your systems, reduce costs, and ensure the quality and safety of the processes you manage.

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