Environmental Applications Bulletin – MyronLMeters.com

Posted by 4 Oct, 2012

TweetEnvironmental Applications Keeping the water in our lakes, rivers, and streams clean requires monitoring of water quality at many points as it gradually makes its way from its source to our oceans. Over the years ever-increasing environmental concerns and regulations have heightened the need for increased diligence and tighter restrictions on wastewater quality. Control of […]

Environmental Applications
Keeping the water in our lakes, rivers, and streams clean requires monitoring of water quality at many points as it gradually makes its way from its source to our oceans. Over the years ever-increasing environmental concerns and regulations have heightened the need for increased diligence and tighter restrictions on wastewater quality. Control of water pollution was once concerned mainly with treating wastewater before it was discharged from a manufacturing facility into the nation’s waterways. Today, in many cases, there are restrictions on wastewater that is discharged to city sewer systems or to other publicly owned treatment facilities. Many jurisdictions even restrict or regulate the runoff of storm water — affecting not only industrial and commercial land, but also residential properties as well.

In its simplest form, water pollution management requires impoundment of storm water runoff for a specified period of time before being discharged. Normally, a few simple tests such as pH and suspended solids must be checked to verify compliance before release. If water is used in any way prior to discharge, then the monitoring requirements can expand significantly. For example, if the water is used for once-through cooling, testing may include temperature, pH, total dissolved solids (TDS), chemical oxygen demand (COD), and biochemical oxygen demand (BOD), to name a few.

Once water is used in a process, some form of treatment is often required before it can be discharged to a public waterway. If wastewater is discharged to a city sewer or publicly owned facility, and treatment is required, the quality is often measured and the cost is based not only on the quantity discharged, but also the amount of treatment required. As a minimum requirement suspended solids must be removed. Filtering or using clarifiers often accomplishes such removal. Monitoring consists of measuring total suspended solids (TSS) or turbidity.

If inorganic materials have been introduced into the water, their concentration must be reduced to an acceptable level. Inorganics, such as heavy metals, typically are removed by raising the pH to form insoluble metal oxides or metal hydroxides. The precipitated contaminants are filtered or settled out. Afterward, the pH must be adjusted back into a “normal” range, which often requires continuous monitoring of pH.

Organic materials by far require the most extensive treatment. Many different methods have been devised to convert soluble organic compounds into insoluble inorganic matter. Most of these involve some form of biological oxidation treatment. Bacteria are used to metabolize the organic materials into carbon dioxide and solids, which can be easily removed. To insure that these processes work smoothly and efficiently requires regular monitoring of the health of the biological organisms. The level of food (organic material), nutrients (nitrogen and phosphorous), dissolved oxygen, and pH are some of the parameters that must be controlled. After bio-oxidation the wastewater is filtered or clarified. Often the final effluent is treated with an oxidizing compound such as chlorine to kill any remaining bacterial agents, but any excess oxidant normally must be removed prior to discharge. Oxidation Reduction Potential (ORP)/Redox is ideal for monitoring the level of oxidants before and after removal. The final effluent stream must be monitored to make sure it meets all regulatory requirements.

The monitoring of wastewater pollution does not end there. Scientists are continuously testing water in streams, ground water, lakes, lagoons, and other bodies of water to determine if and what effects any remaining contamination is having on the receiving waters and its associated aquatic life. Measurements may include pH, conductivity, TDS, temperature, dissolved oxygen, TSS and organic levels (COD and BOD).

Environmental testing is not limited to monitoring of wastewater systems. Control of air emissions often includes gas-cleaning systems that involve the use of water. Wet scrubbers and wet electrostatic precipitators are included in this group. A flue gas desulfurization (FGD) system is one type of wet scrubber that uses slurry of lime, limestone, or other caustic material to react with sulfur compounds in the flue gas. The key to reliable operation of these units is proper monitoring of solids levels and pH. After use, the water in these systems must be treated or added to other wastewater from the plant, where it is treated by one of the methods previously discussed.
With proper monitoring, systems that maintain cleaner air and water can be operated efficiently and effectively. Such operation will go a long way toward maintaining a cleaner environment for future generations.

Myron L Meters offers a full line of handheld instruments and in-line monitor/controllers that can be used to measure or monitor many of the parameters previously mentioned. The following table lists some of the model numbers for measuring, monitoring, or controlling pH, conductivity, TDS and ORP. For additional information, please refer to our data sheets or Ask An Expert at MyronLMeters.com.

Note: When using a monitor/controller to measure pH in streams that contain heavy metals, sulfides, or other materials that react with silver, Myron L Meters recommends using a double junction pH sensor with a potassium nitrate (KNO3) reference gel to avoid fouling the silver electrode. See our 720II Sensor Selection Guide for pH and ORP Monitor/controllers for more information.
Recommended handheld:

Ultrameter II 6P

 

 

 

 

 

 

 

 

http://www.myronlmeters.com/Ultrameter-II-6P-Multiparameter-Meter-p/dh-umii-6pii.htm

Multi-Parameter: Conductivity, TDS, Resistivity, pH, ORP, Temperature, Free Chlorine (FCE)
+/-1% Accuracy of Reading
Memory Storage: Save up to 100 samples w/ Date & Time stamp
Wireless Download Module Optional
Waterproof

 

Categories : Case Studies & Application Stories, Science and Industry Updates

Buying and Using a pH Meter for Food Processing – MyronLMeters.com

Posted by 2 Oct, 2012

TweetWhat is pH and why do I need to measure it? pH measures the amount of acidity or alkalinity in a food or solution using a numerical scale between  1 and 14. A pH value of 1 is most acidic, a pH value of 7 is neutral, and values above 7 are referred to as […]

What is pH and why do I need to measure it?

pH measures the amount of acidity or alkalinity in a food or solution using a numerical scale between  1 and 14. A pH value of 1 is most acidic, a pH value of 7 is neutral, and values above 7 are referred to as basic or alkaline. Acidified foods have a pH value less than or equal to 4.6. The proper pH of a canned food product can be critical to ensuring the safety of the product. It is very important that pH testing be done correctly and accurately.

How is pH measured?

If you process acidified foods, you will be required to monitor the pH of the product that you produce. Depending on the pH of the product, you may be able to use paper pH strips (often referred to as litmus paper), or required to use a pH meter. Paper strips that measure pH rely on a color change in the paper to indicate product pH. Paper strips can be used to measure pH if the product pH is less than 4.0. Paper strips are an inexpensive way to test pH, but can be inaccurate or difficult to read. A pH meter measures the amount of hydrogen-ion (acid) in solution using a glass electrode immersed in the solution. A pH meter must be used when product pH is greater than, or equal to, 4.0. If you are canning acidified foods, accurately monitoring and recording the product pH is key to knowing that you are selling a safe product.

What is equilibrium pH?

Equilibrium pH is the pH of a food product after the added acid has reached throughout the food; the pH of the acid brine and the food that have equilibrated.  When you monitor pH as part of process monitoring, it is the equilibrium pH that you are measuring. For a proper pH reading, you should test the pH of the product roughly 24 hours after processing, once the jars have cooled to room temperature and stabilized. Do not take the pH of a product just before or right after canning because it will not be an accurate measure of the equilibrium pH.

What should I look for if I need to purchase a pH meter?

If you are required to check your product pH with a meter, there are several things to consider.

Accuracy. Accuracy is listed as a range of +0.XX pH units. This means that the meter may read so many pH units above or below the actual pH of the product. Purchase a pH meter with an accuracy of +0.02 units or better. For instance, a pH meter with an accuracy of

+0.01 is a good choice. A pH meter with an accuracy of +0.10 is not a good choice, it is not accurate enough for all products.

Calibration.

All pH meters must be calibrated (checked against a known standard) to assure accuracy. Standards are colored liquids of known pH. Buy a meter that uses at least a 2-point calibration; for acidified foods you will calibrate your meter with pH 4.0 and 7.0 buffers.

Electrode. The electrode is the part of the instrument that is immersed in solution. When considering which pH meter to purchase, consider the cost of replacement electrodes. Some  electrodes  have  special  non-clog  tips  and  these  may  be  useful  is  you  will  be measuring the pH of foods that are not easily blended.

Temperature. pH readings are affected by temperature. In order to get an accurate reading, the pH meter must be calibrated at the same temperature as the samples being tested. More expensive meters will compensate for variations in sample temperature (too warm or too cold). Myron L meters have automatic temperature compensation. If you can afford a meter with this feature, it’s nice to have.

What should I buy?

The cost of a pH meter ranges from under $100 to well over $500.  As a starting point, there are several styles that small food and beverage processors currently use.

Testing the Equilibrium pH of an Acidified Food Product

1.   Open one jar and take a representative sample of your food product once it has cooled, usually 12 to 24 hours after processing. You should sample each batch. Heating will drive the acid into your food product; sampling after processing (and cooling) will give you an accurate reading of the equilibrium pH.

2.   Strain the solids, draining out the liquid (brine) from the jar. Place the strained solids into a blender.

3.   Blend the product, adding distilled water if necessary, to produce a slurry. Added distilled water will not change the pH of the product and will allow for effective blending. You can purchase distilled water at many grocery stores or drug stores.

4.   Use a calibrated pH meter to measure pH.

The pH meter must be calibrated using at least 2-point calibration with pH 4.0 and 7.0 buffers. Myron L Meters recommends a three point calibration.

The pH meter must be calibrated each day that you use it. A pH meter must be used to monitor the pH of foods with an equilibrium pH greater than 4.0.

5.   Record the results in your batch log.

*Myron L meters are used by Tyson, Sara Lee, Gordon Food Service, Better Baked Foods, Schreiber Foods, Homestead Slow Foods, and others in the food

processing industry.

These are our two most popular handheld pH meters:

Ultrapen PT2

 

 

 

 

 

 

https://www.myronlmeters.com/Ultrapen-PT2-Multiparameter-Meter-p/dh-up-pt2-ss.htm

ULTRAPEN PT2 pH and Temperature Pen

Accuracy of +/- 0.01 pH

Reliable Repeatable Results

Easy Calibration

Automatic Temperature Compensation

Measures Temperature

Durable, Fully Potted Circuitry

Waterproof

Comes with 2oz bottle of pH Storage Solution

 

 

 

 

 

 

 

Ultrameter II – 6PII

http://www.myronlmeters.com/Ultrameter-II-6P-Multiparameter-Meter-p/dh-umii-6pii.htm

Multi-Parameter: Conductivity, TDS, Resistivity, pH, ORP, Temperature, Free Chlorine (FCE)

+/-1% Accuracy of Reading

Memory Storage: Save up to 100 samples w/ Date & Time stamp

Wireless Download Module Optional

Waterproof

 

Categories : Application Advice, Case Studies & Application Stories, Technical Tips

pH and pH Meters – MyronLMeters.com

Posted by 24 Sep, 2012

TweetWhat is pH? pH measures the activity of the (solvated) hydrogen ion. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic or alkaline. The pH scale is traceable to a set of standard solutions […]

What is pH?

pH measures the activity of the (solvated) hydrogen ion. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic or alkaline. The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Measuring pH for aqueous solutions can be done with a glass electrode and a pH meter, or using indicators.

Measuring pH is important in water treatment, medicine, biology, chemistry, agriculture, forestry, food science, environmental science, oceanography, civil engineering, chemical engineering, and many other applications.

p[H] was first introduced by Danish chemist Søren Peder Lauritz Sørensen at the Carlsberg Laboratory in 1909 and revised to the modern pH in 1924 to accommodate definitions and measurements in terms of electrochemical cells.  According to the Carlsberg Foundation pH stands for “power of hydrogen”.

pH is defined as the decimal logarithm of the reciprocal of the hydrogen ion activity, aH+, in a solution.

pH Meters

A pH meter is an electronic device used for measuring the pH (acidity or alkalinity) of a liquid (though special probes are sometimes used to measure the pH of semi-solid substances). A typical pH meter consists of a special measuring probe (a glass electrode) connected to an electronic meter that measures and displays the pH reading.

The probe

The pH probe measures pH as the activity of the hydrogen cations surrounding a thin-walled glass bulb at its tip. The probe produces a small voltage (about 0.06 volt per pH unit) that is measured and displayed as pH units by the meter. For more information about pH probe care or replacement, please consult your Myron L meter operations manual.

Calibration and use

*Please consult your Myron L meter operations manual before calibrating.

For very precise work the pH meter should be calibrated before each measurement. For normal use calibration should be performed at the beginning of each day. The reason for this is that the glass electrode does not give a reproducible e.m.f. over longer periods of time. Calibration should be performed with at least two standard buffer solutions that span the range of pH values to be measured. For general purposes buffers at pH 4 and pH 10 are acceptable. The pH meter has one control (calibrate) to set the meter reading equal to the value of the first standard buffer and a second control (slope) which is used to adjust the meter reading to the value of the second buffer. A third control allows the temperature to be set. Standard buffer solutions, which can be obtained from MyronLMeters.com here:

http://www.myronlmeters.com/pH-Buffer-Calibration-Solutions-s/82.htm

usually state how the buffer value changes with temperature. For more precise measurements, a three buffer solution calibration is preferred. As pH 7 is essentially, a “zero point” calibration (akin to zeroing a scale), calibrating at pH 7 first, calibrating at the pH closest to the point of interest ( e.g. either 4 or 10) second and checking the third point will provide a more linear accuracy to what is essentially a non-linear problem. Some meters will allow a three point calibration and that is the preferred scheme for the most accurate work, and is recommended by Myron L Meters. Higher quality meters will have a provision to account for temperature coefficient correction, and high-end pH probes have temperature probes built in. The calibration process correlates the voltage produced by the probe (approximately 0.06 volts per pH unit) with the pH scale. After each single measurement, the probe is rinsed with distilled water or deionized water to remove any traces of the solution being measured, blotted with a scientific wipe to absorb any remaining water which could dilute the sample and thus alter the reading, and then quickly immersed in another solution.

Storage conditions of the glass probes

When not in use, the glass probe tip must be kept wet at all times to avoid the pH sensing membrane dehydration and the subsequent dysfunction of the electrode. You can get your sensor storage solution here:

http://www.myronlmeters.com/pH-Storage-Solution-p/s-ssq.htm

A glass electrode alone (i.e., without combined reference electrode) is typically stored immersed in an acidic solution of around pH 3.0. In an emergency, acidified tap water can be used, but distilled or deionised water must never be used for longer-term probe storage as the relatively ionless water “sucks” ions out of the probe membrane through diffusion, which degrades it.

Combined electrodes (glass membrane + reference electrode) are better stored immersed in the bridge electrolyte (often KCl  3 M) to avoid the diffusion of the electrolyte (KCl) out of the liquid junction.

Cleaning and troubleshooting of the glass probes

Occasionally (about once a month), the probe may be cleaned using pH-electrode cleaning solution; generally a 0.1 M solution of hydrochloric acid (HCl) is used, having a pH of one.

In case of strong degradation of the glass membrane performance due to membrane poisoning, diluted hydrofluoric acid (HF < 2 %) can be used to quickly etch (< 1 minute) a thin damaged film of glass. Alternatively a dilute solution of ammonium fluoride (NH4F) can be used. To avoid unexpected problems, the best practice is however to always refer to the electrode manufacturer recommendations or to a classical textbook of analytical chemistry.

Types of pH meters

A pH meter for every industry

pH meters range from simple and inexpensive pen-like devices to complex and expensive laboratory instruments with computer interfaces and several inputs for indicator and temperature measurements to be entered to adjust for the slight variation in pH caused by temperature. Specialty meters and probes are available for use in special applications, harsh environments, etc. Myron L Meters offers a simple pen-style pH meter, analog handheld meters, digital handheld multiparameter meters, and inline monitor/controllers.

Myron L Ultrapen PT2 pH and Temperature Tester

 

 

 

 

 

 

 

 

https://www.myronlmeters.com/Ultrapen-PT2-Multiparameter-Meter-p/dh-up-pt2-ss.htm

ULTRAPEN PT2 pH and Temperature Pen

Accuracy of +/- 0.01 pH

Reliable Repeatable Results

Easy Calibration

Automatic Temperature Compensation

Measures Temperature

Durable, Fully Potted Circuitry

Waterproof

Comes with 2oz bottle of pH Storage Solution

 

 

Myron L AG-6 TDS and pH meter

 

 

 

 

 

 

 

 

 

http://www.myronlmeters.com/Analog-pH-Conductivity-Meter-p/ah-ds-ag6-fslash-ph.htm

 

Agri-Meter – Ag-6: 0-5 millimhos; 2-12 pH

Instant and accurate TDS tests

Electronic Internal Standard for easy field calibration

Fast Auto Temperature Compensation

Rugged design for years of trouble-free testing

Simple to use

 

Myron L Ultrameter II 6P multiparameter meter

 

 

 

 

 

 

 

 

 

http://www.myronlmeters.com/Ultrameter-II-6P-Multiparameter-Meter-p/dh-umii-6pii.htm

 

 

Multi-Parameter: Conductivity, TDS, Resistivity, pH, ORP, Temperature, Free Chlorine (FCE)

+/-1% Accuracy of Reading

Memory Storage: Save up to 100 samples w/ Date & Time stamp

Wireless Download Module Optional

Waterproof

 

Myron L 723II digital inline pH monitor/controller

 

 

 

 

 

 

 

 

 

http://www.myronlmeters.com/Inline-pH-Digital-Monitor-Controller-p/i-dmc-723ii.htm

 

The advanced “isolated” circuitry of the 720 Series II pH/ORP Monitor/ controllers guarantees accurate and reliable measurements — completely eliminating ground-loop and noise issues.

 

The unique sensor preamp allows for longer distances between the sensor and the Monitor/controller without the loss of accuracy or reliability.

 

All Myron L Monitor/controllers feature a highly refined and precise Temperature Compensation circuit. This feature perfectly matches the NERNST equation correcting the displayed reading to 25′C. The TC may be disabled to conform to USP requirements.

 

 

Categories : Product Updates, Science and Industry Updates

Boiler and Cooling Tower Water – MyronLMeters.com

Posted by 15 Sep, 2012

TweetBoilers and cooling towers share two major water related problems: deposits and corrosion. As a boiler or water evaporating from a cooling tower generates steam, dissolved minerals are left behind, increasing the concentration of these minerals. Additional minerals are introduced via the water added to makeup the water lost to steam/evaporation. Eventually, the minerals reach […]

Boilers and cooling towers share two major water related problems: deposits and corrosion. As a boiler or water evaporating from a cooling tower generates steam, dissolved minerals are left behind, increasing the concentration of these minerals. Additional minerals are introduced via the water added to makeup the water lost to steam/evaporation. Eventually, the minerals reach a level (or cycle) of concentration that will cause either loss of efficiency due to scale or damage from corrosion. This level can be determined by the Ryznar or Langlier indices and correlated to a conductivity or TDS range. Most people recognize problems associated with corrosion. Effects from scale deposits, however, are equally important. For example, as little as 1/8″ of scale can reduce the efficiency of a boiler by 18% or a cooling tower heat exchanger by 40%!

A variety of water treatment methods are employed in an effort to control these problems. Even with water treatment, it is still necessary to regularly blow down or bleed off part of the concentrated water and make up with lower salinity water to reduce the overall mineral concentration.

To conserve water and treatment chemicals, it is desirable to allow the dissolved minerals to reach a maximum cycle of concentration while still avoiding problems. Because feed water/make-up waters vary in the types and amounts of minerals present, the allowable cycles of concentration will vary. As a result, regular testing of boiler and cooling waters is essential to optimize water treatment programs and blow down schedules. Tests commonly performed include conductivity or TDS, pH and ORP. Myron L meters provide you with a simple, fast, and accurate means of testing these parameters.

Many cooling towers and boilers have inline controllers used to release water from the tower or boiler and feed chemical(s) into the system. The controllers must be calibrated regularly to ensure fouling or drift of the sensor has not occurred. Our portable instruments in conjunction with NIST traceable standard solutions provide rapid verification of the accuracy of inline controllers. This method reduces manpower and the likelihood of disturbing or damaging sensors.

Conductivity

Conductivity is the measurement of a solution’s ability to transmit an electrical current. It is usually expressed in microsiemens/cm (micromhos/cm). Pure water is actually a poor electrical conductor (18,200,000 ohms/cm of resistance). It is the amount of ionized substances (or salts) dissolved in water, which determines the conductivity. Because the vast majority of the dissolved minerals in water are these conductive inorganic impurities, conductivity measurement is an excellent indicator of mineral concentration.

Myron L meters were developed for just this purpose. Models are available which display conductivity and/or ppm of TDS. For detailed information regarding the relationship between conductivity and TDS, please see the our Application Bulletin: Standard Solutions and Buffers.

pH

pH, the measurement of acid or base, is one of the most important factors affecting scale formation or corrosion in a boiler or cooling system. The types of impurities comprising the mineral concentration behave differently at various pHs. Low pH waters have a tendency to cause corrosion, while high pH waters may cause scale formation.

Boiler water

Boiler water requirements can range from very pure to more than 6500 microsiemens, depending on size, pressure, application, and feed water. Once the maximum cycles of concentration has been established, a conductivity instrument can conveniently help you to determine if the blow down schedule is adequate. Samples should be cooled to at least 160°F/71°C to ensure accurate temperature compensated readings.

Boiler condensate

Boiler condensate samples are often tested to determine if there is any carryover of boiler water solids or contaminants entering from outside the system. Condensate is relatively pure water, and values of 2-100 microsiemens are common. Because of these low values, a multiple-range instrument is recommended to increase the resolution and accuracy of the reading. Monitoring the pH of condensate is also important since condensate is very corrosive at low pHs. Treatment additives are often added to elevate the pH to minimize corrosion in condensate lines.

Cooling tower water

Cooling tower water has become more challenging since the reduced use of acid and the elimination of chromate. Monitoring conductivity and pH has become imperative to maintain a proper treatment program. Although many systems have controls on these parameters, the possibility of a system upset is always present. Even slight upsets can cause rapid scaling of heat exchangers.

Biological Growth

Biological growth is another extremely important facet to proper cooling water management. Microbes can cause corrosion, fouling, and disease. Oxidizing biocides (chlorine, chlorine dioxide, ozone and bromine) have been employed to keep bacteria under control. Monitoring of the ORP (Oxidation Reduction Potential)/redox is very useful in its ability to correlate millivolt readings to sanitization strength of the water. The ULTRAMETER II™ 6P includes this parameter for quick on-site determinations.

Ultrameter II 4P  Ultrameter II 6P  TechPro II TH1  TechPro II TP1  TechPro II TPH1  M6/pH

EP11/pH   512M5   EP10  EP  inline monitors/controllers

Categories : Application Advice, Technical Tips

Reverse Osmosis and Measurement for Home and Commercial Systems

Posted by 23 Aug, 2012

Tweet OSMOSIS Osmosis is the phenomenon of lower dissolved solids in water passing through a semi-permeable membrane into higher dissolved solids water until a near equilibrium is reached. Reverse Osmosis (RO) is a membrane process of purification which removes most of the total dissolved solids (TDS) in water by reversing the natural process of osmosis. […]

OSMOSIS

Osmosis is the phenomenon of lower dissolved solids in water passing through a semi-permeable membrane into higher dissolved solids water until a near equilibrium is reached. Reverse Osmosis (RO) is a membrane process of purification which removes most of the total dissolved solids (TDS) in water by reversing the natural process of osmosis. Pressure is applied to a TDS-concentrated solution against a semi-permeable membrane, causing pure water to diffuse through the membrane. RO has become an important process for a wide variety of applications including: medical, laboratory, desalination, industrial wastewater, Deionized (Dl) pretreatment, and drinking water.

TESTING RO WATER QUALITY

Electrical conductivity is the most convenient method for testing RO water quality and membrane performance. Pure water is actually a poor electrical conductor. The amount of ionized substances (salts, acids, or bases) dissolved in water determines its conductivity. Normally, the vast majority of the dissolved minerals in tap, surface or ground water are conductive impurities. Myron L Company has conducted extensive research relating conductivity to TDS, resulting in instrumentation and calibration solutions which have become the standard of the RO industry.

When calibrating your conductivity instrument for testing fresh water, the “442 Natural Water Standard™” solutions are the best choice. These solutions are available in various concentrations.
442 solutions contain the following salts diluted in pure water: 40% sodium bicarbonate, 40% sodium sulfate and 20% sodium chloride. These are the most common salt compounds in surface and ground water. A sodium chloride solution provides better results in brackish or sea water because the predominant salt in these waters is sodium chloride.

ORP

ORP (Oxidation Reduction Potential/REDOX) and pH are important parameters in measuring the success and useful life of an RO membrane. The ORP may be used to determine the activity of an oxidizer. RO membranes are susceptible to attack by oxidizers such as chlorine, bromine, ozone and hydrogen peroxide. The activity of the oxidizer is more informative than the chemical residual because it determines the ability and speed of oxidation. A high ORP reading would indicate a need for pretreatment. A low ORP may indicate biological activity which may cause fouling of the membranes.

ORP can also be used to determine an overfeed of sodium bisulfite, which is used to reduce chlorine. If the ORP reading is under 200 mV, you have a reducing condition. This overfeed costs extra money and can lead to environmental discharge problems. It is best to check the reject water, where the concentration is highest. This will show even minute quantities of oxidizers or reducers.

pH

pH is very useful in predicting membrane life and the scaling potential of feedwater. The higher the pH and calcium, the more likely it is that scale will form on the membranes. However, with silicon based compounds, a low pH will increase the tendency for scaling. Membranes also have a pH range where operation is optimal. It is often useful to check the pH of the reject water to help determine scaling potential.

HOME SYSTEMS
Myron L Meters carries single and multiple range handheld instruments. Model RO-1 and RO-1NC are reliable, single range instruments used to demonstrate the RO process to a prospective buyer. The color coding of the model RO-1 dial dramatizes the difference between high TDS (red- above EPA recommended limits for drinking water), medium TDS (orange – within EPA recommended standards for drinking water), and low TDS RO water (blue-high purity water). Installers prefer the three range 532 models or TechPro II™ TP1 or TPH1 because they are ideal for accurately testing both feed and product water.

COMMERCIAL/INDUSTRIAL
Larger RO systems such as those found in bottled water plants, hospitals, industrial process, or seawater desalination require continuous monitoring to verify water quality and membrane condition. For continuous measurement of water quality, Myron L Meters carries the 720 and 750 Series II Monitor/ controllers. Monitor only, and monitor/controller models are available. Monitor/controller models contain an adjustable set point and a heavy-duty 10 amp relay which can be used to activate alarms, valves, autodialers, etc. A variety of options and outputs are available to cost-effectively tailor the monitor to the particular RO application.

The Ultrameter™ 9PTK, 6PII and 4PII are preferred by water treatment professionals for calibrating and checking Commercial/industrial RO systems. They appreciate the waterproof case, ability to store and record 100 memory data records, and three preprogrammed solution curves. Ultrameters are compact, but their multiple parameters give them the versatility of several instruments.

Myron L Meters also carries pen style meterss for dip or scoop sampling. The ULTRAPEN PT1 delivers stable, lab-accurate readings of Conductivity, TDS, Salinity and Temperature. The PT2 pH and Temperature pen is also available for spot checks and pretreatment screening. Both pens are waterproof, durable, and easy to use with one-button functioning.

Visit us here to save 10% on any of our Myron L meters: http://www.myronlmeters.com/Digital-Multiparameter-Meters-s/48.htm

Categories : Product Updates, Science and Industry Updates

Myron L Meters Thanks Mill Brook Bonsai!

Posted by 5 Jul, 2012

Tweet Nestled in the foothills of the Green Mountains of Vermont with a trout stream behind the nursery, Mill Brook Bonsai is devoted to the art of Bonsai.  Founded in 1997 after many years as a hobby, the nursery has grown to include native trees, tropical trees and imported trees as well as tools, pots […]

Ultrapenpt2_2

Nestled in the foothills of the Green Mountains of Vermont with a trout stream behind the nursery, Mill Brook Bonsai is devoted to the art of Bonsai.  Founded in 1997 after many years as a hobby, the nursery has grown to include native trees, tropical trees and imported trees as well as tools, pots and accessories.

Come and visit, feed the attack-trained Koi in our small pond and enjoy the quiet and serenity that is associated with this ancient Chinese and Japanese art form.

Mill Brook Bonsai was founded in 1997 after Sandy & Trudy Anderson had spent a number of years as amateur bonsaiists.  The first greenhouse went up in ‘97, the second one, for tropical trees a few years later and then, as the collection grew, a third greenhouse was added.  Much of our initial knowledge came from such folk as Gil Klein, a bonsaiist who moved to VT from the NY area.  Later, Eric Schalk  of Waterbury, VT added his knowledge to our early store of information and then, over the past years, David Easterbrook, Curator of the Bonsai Exhibit at the Montreal Botanical Gardens has graced us with his talents.

Over the years we have been fortunate enough to have guest speakers here such as Suthin Sukolsovisit, Harry Thomlinson, Chase Rosade, Mary Miller, Mike Sullivan, Colin Lewis and a host of others that have added to our own knowledge as well as the members of Green Mountain Bonsai Society who have hosted many of these events.

 We have a large number of trees ranging in price from $45 to $2,000.  There is a tree for every budget and for every environment.  Here is a photograph of recently arrived Chinese Elms in the foreground; Taiwan Figs appear to the front left of the picture.

Myron L Meters is proud to do business with Mill Brook Bonsai.

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http://www.myronlmeters.com

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Categories : MyronLMeters.com Valued Customers, Uncategorized

How to measure swimming pool water quality

Posted by 28 Jan, 2011

TweetIn order to test the swimming pool water quality, you need to know what you’re testing. Some of the basic parameters that are measured for pools include pH, Chlorine, Total Alkalinity, Calcium Hardness, and Total Dissolved Solids. A balanced swimming pool really only needs to have the pH and chlorine levels checked and corrected on […]

In order to test the swimming pool water quality, you need to know what you’re testing. Some of the basic parameters that are measured for pools include pH, Chlorine, Total Alkalinity, Calcium Hardness, and Total Dissolved Solids.

A balanced swimming pool really only needs to have the pH and chlorine levels checked and corrected on a regular basis, the other chemical values being measured less frequently.
Myron L PoolPro Pool Test

Many swimming pool and spa professionals use portable instruments to test the water quality during treatment. If you are a homeowner with a pool, you may want to consider using an instrument as opposed to the simple test kits with liquid droplets or tablets. If you need an instrument, check out the selection here: MyronLMeters.com. The instruments are much more accurate and can provide immediate, reliable results. If you are using the test kits, there are a few things to note. Expired tablets/ test liquids (reagents) should be thrown out as they very often give inaccurate readings, resulting in improper treatment, wasting expensive chemicals and possibly damaging the pool and filtration equipment. Always keep the test kit in a cool dry place out of the sun and out of the reach of children.

When testing the pool water, rinse the cell cups of your instrument or test kit thoroughly before filling them with water from at least 20-30 cm below the surface of the swimming pool. When you’re finished testing the water be sure not to pour the samples back into the pool.

As a general rule of thumb, tests for pH and chlorine should be done weekly. If there are no obvious problems in your swimming pool (algae growth, cloudy water, lime scale buildup, etc) then you can test for Total Alkalinity, Calcium Hardness, and Total Dissolved Solids approximately every month.

Swimming pool chemistry can seem intimidating, so consulting a swimming pool professional is not a bad idea. Some will visit your pool and perform the test or you can take a sample directly to your local pool supply store and they may be able to test it for you.

If the water in your area is free from any metals and your swimming pool shows none of the symptoms of iron or copper presence, the test for these metals is unnecessary. If, however, you notice staining on the walls and floor of the swimming pool, you should have the levels of these metals checked and treated if necessary.

For a more in-depth study of pool water testing, visit the link below:

http://www.deh.enr.state.nc.us/ehs/quality/wph.htm

The Association of Pool and Spa Professionals (APSP) is a great resource for individuals and companies that want to learn more about water treatment for pools and spas.

Categories : Application Advice, Technical Tips

Posted by 23 Jan, 2011

Tweet Basic Tips For Choosing The Proper Instrument For Water Quality Tests

Basic Tips For Choosing The Proper Instrument For Water

Quality Tests

Categories : Uncategorized

6 Tips for Measuring pH of Pure DI Water

Posted by 28 Dec, 2010

TweetMeasuring the pH of pure DI water is easy when you know what to expect. In theory, pure water should have a pH of 7. When you actually measure the pH, it will most likely fall between 5.5 and 7 due to its absorption of CO2 from the atmosphere. This natural occurrence forms carbonic acid […]

Measuring the pH of pure DI water is easy when you know what to expect. In theory, pure water should have a pH of 7. When you actually measure the pH, it will most likely fall between 5.5 and 7 due to its absorption of CO2 from the atmosphere. This natural occurrence forms carbonic acid in the water, lowering the pH. Since DI water is pure, there is nothing to buffer it and stabilize the pH. Below are a few tips to increase the accuracy of your pH measurements.

Tips for accurate pH readings

  1. First and foremost, use a high quality ph meter and ensure that it is properly calibrated with pH buffer solution. Check the manufacturer’s recommendations for calibration. The Ultrameter II 6P and the Techpro II TPH1 are portable pH meters that are extremely accurate and easy to use.
  2. When using a portable pH meter, avoid cross-contamination by thoroughly rinsing with the DI water that you will be sampling. If a glass beaker or cup is to be used, rinse that as well.
  3. Use small samples and minimize exposure to air, as this will lower the pH value. Taking samples from an open-air drum or tank will typically give erroneous readings. Collect samples from a sample port if possible.
  4. If you have access to high-purity reagent grade KCl (Potassium Chloride) salts, then you can buffer the DI water to stabilize the pH. Adding a tiny amount to the pure DI water sample will increase the ionic strength and reduce the absorption of CO2 from the atmosphere. Be careful not to contaminate the KCl salts. Use proper tools/utensils to add the KCl salts
  5. If no salt is available and all you need is a quick check of your system, you can flow the water from a sample port into your portable pH meter to measure the pH values. This will take slightly longer to stabilize. Be sure to use an accurate, waterproof pH meter and hold it closely to the sample port.
  6. Changes in temperature can affect the pH. Use a pH meter that is temperature compensated to remedy this issue.

If you need pH buffer solution, you can find it here at an affordable price.

Categories : Application Advice, Technical Tips

How Water Quality Affects Greenhouse Crops

Posted by 28 Dec, 2010

Tweet If you are a greenhouse grower then you are most likely familiar with the importance of proper water quality for your crops. Water quality can easily be determined by taking measurements periodically. It is important to use accurate and reliable equipment to perform the measurements. A wide selection of high quality conductivity testers and […]

greenhouse drip

If you are a greenhouse grower then you are most likely familiar with the importance of proper water quality for your crops. Water quality can easily be determined by taking measurements periodically. It is important to use accurate and reliable equipment to perform the measurements. A wide selection of high quality conductivity testers and hydroponic pH testers can be found here at an affordable price.

To determine the suitability of water for irrigation you can easily take measurements of the Electrical Conductivity (EC) and the Sodium Adsorption Ratio (SAR). In general, the higher the EC and SAR, the less suitable the water is for irrigation. Irrigation using water with high sodium adsorption ratio may require soil amendments to prevent long-term damage to the soil.

SAR measurements are provided with laboratory analysis of the water. However, EC measurements can be made using a portable EC meter. The Myron L AG6/pH was specifically designed as a pH and conductivity tester for greenhouse crops.

As a rule of thumb, the water is considered borderline and its use can present problems if conductivity values are higher than 0.8 millisiemens/cm (mS) and SAR is over 4. If the conductivity measurement is below 0.8 mS and the SAR measurement is below 4, the water is suitable for greenhouse irrigation. Particular management practices should be used when water is outside the acceptable limits. This might include using a growing medium with excellent drainage, leaching with every watering and compensating the sodium with calcium and magnesium.

If galvanized steel is used throughout the greenhouse and water is reclaimed for irrigation, it is a good idea to check the amount of Zinc in the water and make nutrient correction accordingly.

Many greenhouses use drip irrigation systems, which are efficient and low maintenance, but nozzles can become clogged by hard water. Check for high levels of bicarbonates (above 100 ppm) in the water and neutralize with the appropriate acids.

There are many factors that affect water quality and greenhouse crop growth. Consult your fertilizer manufacturer for recommendations on proper nutrient levels.

Categories : Application Advice, Technical Tips