Frequently Asked Questions – MyronLMeters.com
TweetHow long will my Standard Solutions and Buffers last? The warranty on all standards and buffers is one year from the date it is manufactured (see the label on the bottle). If the standards and buffers become contaminated by the user pouring test samples back into the bottle or inserting the probe into the bottle [...]
How long will my Standard Solutions and Buffers last?
The warranty on all standards and buffers is one year from the date it is manufactured (see the label on the bottle). If the standards and buffers become contaminated by the user pouring test samples back into the bottle or inserting the probe into the bottle the solution will not be accurate and should be discarded. The life of standards and buffers can exceed 1 year if the bottle is stored tightly capped and is not exposed to direct sunlight or freezing temperatures. If the solution becomes frozen, do not remove the cap – allow the standard or buffer solution to thaw completely and shake the bottle vigorously before opening.
How do I clean the conductivity cell cup on the handheld units?
With everyday sampling, the cell cup may build up a residue or film on the cell walls that may cause the readings to become erratic. Use a 50/50 mixture of a common household cleaner (i.e. Lime-A-Way, CLR, Tilex, etc) and DI water. Pour into conductivity cell cup and scrub with a q-tip. Be sure to get around all the electrodes and the thermistor probe. On the DS handheld unit, use an acid brush to scrub the cell cup. Let it set for about 10 minutes. Rinse the cell cup thoroughly with tap water, then a final rinse with DI water.
The display on my Ultrameter II 6P reads “Error 1″. What does that mean?
This is possibly caused by contamination to the circuit board. One or more of the traces on the PCB have been jumped/bridged and there is a contamination. Possible moisture, condensation, dirt, dried salts or other condensation inside is a potential cause for this display.
Where can I get an operations manual for my meter?
Go to MyronLMeters.com. Click on Manuals and Literature at the top of the page. Once on the Manuals and Literature page, you’ll find application bulletins, operations manuals, material safety data sheets, and product datasheets. All are free, downloadable pdf files.
How do I pick the correct range module for my Monitor or Monitor/Controller?
Pick a range module that covers 2/3 of your operating range. If you pick a range module that is too broad, then your accuracy will suffer or it will not show a number on the display. For example, if your operating range is 100-150 microsiemens, a range module of 0-200 microsiemens (-115) would be a good choice. A range module of 0- 5,000 microsiemens (-123) would not be a good choice for this application
Got questions? Visit us at MyronLMeters.com and Ask An Expert.
Environmental Applications Bulletin – MyronLMeters.com
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
Buying and Using a pH Meter for Food Processing – MyronLMeters.com
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:
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
pH and pH Meters – MyronLMeters.com
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.
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
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
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
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.