Tweet WHY TEST FOUNTAIN SOLUTIONS? Accurate fountain (dampening) solution concentration control is essential for consistent, high-quality results in lithography. Low concentration can cause drying on the non-image area of the plate resulting in tinting, scumming, blanket piling, etc. High concentrations, on the other hand, bring about over-emulsification of the ink. This results in weakening of […]
WHY TEST FOUNTAIN SOLUTIONS?
Accurate fountain (dampening) solution concentration control is essential for consistent, high-quality results in lithography. Low concentration can cause drying on the non-image area of the plate resulting in tinting, scumming, blanket piling, etc. High concentrations, on the other hand, bring about over-emulsification of the ink. This results in weakening of color strength and changes in ink rheology (body and flow properties). Correct concentration will allow the non-image areas of the plate to be appropriately wetted.
WAYS TO TEST
Traditionally, pH was the test relied on to determine fountain solution concentration. Today, however, conductivity testing is recognized as a much more accurate method. Many modern dampening solutions are pH stabilized (or buffered), so only small changes in pH are seen even when dramatic changes occur in solution strength. Conductivity measurement is a fast and easy test which is more indicative of fountain solution concentration than pH. This is true for all neutral, alkaline, and many acid type solutions.
pH is still important, however, with unbuffered acid fountain solutions. Checking both conductivity and pH can provide valuable information. Acid fountain solution is a mixture of gum arabic, wetting agents, salts, acids, buffers, etc. Conductivity will tell you if the proper amount of most ingredients are present, but pH is necessary to check acid concentrations. pH will also determine how effective one ingredient, gum arabic, will be.
What is conductivity? Conductivity is the measurement of a solution’s ability to conduct an electrical current. It is usually expressed in microsiemens (micromhos). Absolutely pure water is actually a poor electrical conductor. It is the substances dissolved in water which determine how conductive the solution will be. Therefore, conductivity is an excellent indicator of solution strength.
To properly measure the conductivity of fountain solutions:
1. Test and write down the conductivity of the water used to prepare the solution.
- Mix the fountain solution concentrate with the water, using the manufacturer’s recommendations or as experience dictates.
- Measure the conductivity of the mixed solution.
- Subtract the water conductivity value obtained in step 1. This is necessary because tap water quality can change from day to day.
The resulting number is an accurate indicator of fountain solution strength. Caution: because alcohol will lower a solution’s conductivity, always test solution conductivity before and after the addition of alcohol.
Determining the best concentration of fountain solution is mostly “trial and error.” It can be very useful to make a graph, recording readings for every one-half or one ounce of concentrate added to a gallon of water. Record readings on a graph with the vertical axis representing conductivity values and the horizontal axis representing ounces/gallon. Such a graph will help “fine tune” your system during future press runs.
For “on the spot” fountain solution tests, Myron L handheld instruments are fast, accurate, and reliable. Measurements are made in seconds simply by pouring a small sample of solution into the instrument cell cup and pressing a button. Automatic temperature compensated accuracy and famous Myron L reliability have made our instruments popular in pressrooms worldwide.
Even though pH usually is not the best method to check the concentration of fountain solution, it is still very important and must be checked regularly. The pH of acid dampening solution affects sensitivity, plate-life, ink-drying, etc. Also, pH can change during a run if the paper has a high acid or alkaline content. pH, therefore, must be maintained at the proper level for good printing.
A convenient and accurate way to test pH (as well as temperature) is Myron L’s waterproof Ultrameter II™ Model 6PFCE or TechPro II™ TH1. The 6PFCE has a 100 reading memory and the TH1 has a 20 reading memory to store test results on site. The 6P also measures conductivity. All electrodes are contained in the cell cup for protection. Model M6/PH also measures pH and conductivity.
For continuous monitoring and/or control of fountain solution concentration, Myron L offers a complete series of in-line conductivity instruments. These economical, accurate, and reliable models use a remotely installed sensor and a panel/wall mount meter enclosure. Most contain an adjustable set point and heavy duty relay circuit which can be used to activate alarms, valves, feedpumps, etc. All models contain a 0-10 VDC output for a chart recorder or PLC (SCADA) input, if required, (4-20 mA output is also available).
The 750 Series II with dual set point option has become quite popular in pressrooms. The two set points allow a “safe zone” for controlling fountain solution concentration.
Ultrameter II 6PFCE, 512M5 and M6/PH are available with the useful LITHO-KIT™. This accessory includes a foam-lined, rugged all-plastic carry case with calibrating solutions and buffers. In addition, a syringe to simplify drawing samples and a thermometer for testing fountain solution temperature are also included.
|Improperly mixed fountain solution||Carefully follow manufacturer’s directions, checking both water and mixed solution with a conductivity instrument||Ultrameter 4PII, 6PIIFCE and 9PTK; ULTRAPEN PT1; and TechPro II TPH1 or TP1 all test 0-9999 ppm TDS or microsiemens conductivity, and temperature. 512M5 por- table DS Meter™ with a 0-5000 microsiemens conductivity range.|
|Halftones sharpen and highlight dots lost during run||Check pH of fountain solution to determine if it’s too acidic||Ultrameter 4PII, 6PIIFCE and 9PTK; ULTRAPEN PT2; and TechPro II TH1.M6/PH portable pDS Meter. Ranges: 0-5000 microsiemens and 2-12 pH.|
|Reverse osmosis water treatment system monitor indicates membrane failure||Test RO water quality and verify in-line instrument accuracy||Ultrameter 4PII, 6PIIFCE and 9PTK; ULTRAPEN PT1; and TechPro II TPH1 or TP1 all test 0-9999 ppm TDS or microsiemens conductivity, and temperature.|
|Scum streaks across plate after 10,000 – 20,000impressions||Check acid/gum levels infountain solution||Ultrameter 6PIIFCE and 9PTK; ULTRAPEN PT2; and TechPro II TH1.M6/PH portable pDS Meter. Ranges: 0-5000 microsiemens and 2-12 pH.|
|Personnel unable to test fountain solution concentration||Continuously control fountain solution with conductivity Monitor/controller||758II-123 (0-5000 µS) in-lineMonitor/controller.|
You can save 10% on any recommended meter at MyronLMeters.com.
Tweet Anyone responsible for operating and maintaining a swimming pool or spa has to test, monitor, and control complex, interdependent chemical factors that affect the quality of water. Additionally, aquatic facilities operators must be familiar with all laws, regulations, and guidelines governing what these parameters should be. […]
Anyone responsible for operating and maintaining a swimming pool or spa has to test, monitor, and control complex, interdependent chemical factors that affect the quality of water. Additionally, aquatic facilities operators must be familiar with all laws, regulations, and guidelines governing what these parameters should be.
Why? Because the worst breeding ground for any kind of microorganism is a warm (enough) stagnant pool of water. People plus stagnant water equals morbid illness. That’s why pools have to be circulated, filtered, and sanitized – with any number of chemicals or methods, but most frequently with chlorine compounds. However, adding chemicals that kill the bad microorganisms can also make the water uncomfortable, and in some cases unsafe, for swimmers. Additionally, if all the chemical factors of the water are not controlled, the very structures and equipment that hold the water and keep it clean are ruined.
So the pool professional must perform a delicate balancing act with all the factors that affect both the health and comfort of bathers and the equipment and structures that support this. Both water balance – or mineral saturation control – and sanitizer levels must constantly be maintained. This is achieved by measuring pertinent water quality factors and adding chemicals or water to keep the factors within acceptable parameters.
Water is constantly changing. Anything and everything directly and indirectly affects the relationship of its chemical parameters to each other: sunlight, wind, rain, oil, dirt, cosmetics, other bodily wastes, and any chemicals you add to it. Balanced water not only keeps swimmers comfortable, but also protects the pool shell, plumbing, and all other related equipment from damage by etching or build-up and stains.
The pool professional is already well acquainted with pH, Total Alkalinity (TA), and Calcium Hardness (CH); along with Total Dissolved Solids (TDS) and Temperature, these are the factors that influence water balance. Water that is in balance is neither aggressive nor oversaturated. Aggressive water lacks sufficient calcium to saturate the water, so it is hungry for more. It will eat anything it comes into contact with to fill its need, including the walls of your pool or spa or the equipment it touches. Over-saturated water cannot hold any more minerals, so dissolved minerals come out of solution and form scale on pool and equipment surfaces.
The pH of pool water is critical to the effectiveness of the sanitizer as well as the water balance. pH is determined by the concentration of Hydrogen ions in a specific volume of water. It is measured on a scale of 0-14, 0-7 being acidic and 7-14 being basic.
You must maintain the pH of the water at a level that assures the sanitizer works effectively and at the same time protects the pool shell and equipment from corrosion or scaling and the bathers from discomfort or irritation. If the pH is too high, the water is out of balance, and the sanitizer’s ability to work decreases. More and more sanitizer is then needed to maintain the proper level to kill off germs. Additionally, pH profoundly affects what and how much chemical must be added to control the balance. A pH of between 7.2 – 7.6 is desirable in most cases.*
As one of the most important pool water balance and sanitation factors, pH should be checked hourly in most commercial pools.* Even if you have an automatic chemical monitor/controller on your system, you need to double- check its readings with an independent pH test. With salt- water pools, pH level goes up fast, so you need to check it more often. Tests are available that require reagents and subjective evaluation of color depth and hue to judge their pH. But different users interpret these tests differently, and results can vary wildly. The PooLPRo and ULTRAPEN PT2 give instant lab-accurate, precise, easy-to-use, objective pH measurements, invaluable in correctly determining what and how much chemical to add to maintain water balance and effective sanitizer residuals.
Total Alkalinity (TA) is the sum of all the alkaline minerals in the water, primarily in bicarbonate form in swimming pools, but also as sodium, calcium, magnesium, and potassium carbonates and hydroxides, and affects pH directly through buffering. The greater the Total Alkalinity, the more stable the pH. In general, TA should be maintained at 80 – 120 parts per million (ppm) for concrete pools to keep the pH stable.* Maintaining a low TA not only causes pH bounce, but also corrosion and staining of pool walls and eye irritation. Maintaining a high TA causes overstabilization of the water, creating high acid demands, formation of bicarbonate scale, and may result in the formation of white carbonate particles (suspended solids), which clouds the water. Reducing TA requires huge amounts of effort. So the best solution to TA problems is prevention through close monitoring and controlling. The PoolPro PS9 Titration Kit features an in-cell conductometric titration for determining alkalinity.
Calcium Hardness (CH) is the other water balance parameter pool professionals are most familiar with. CH represents the calcium content of the water and is measured in parts per million. Low CH combined with a low pH and low TA significantly increases corrosivity of water. Under these conditions, the solubility of calcium carbonate also increases. Because calcium carbonate is a major component of both plaster and marcite, these types of pool finishes will deteriorate quickly. Low CH also leads to corrosion of metal components in the pool plant, particularly in heat exchangers. Calcium carbonate usually provides a protective film on the surface of copper heat exchangers and heat sinks, but does not adversely affect the heating process. Without this protective layer, heat exchangers and associated parts can be destroyed prematurely. At the other extreme, high CH can lead to the precipitation of calcium carbonate from solution, resulting in cloudy water, the staining of structures and scaling of equipment. The recommended range for most pools is 200 – 400 ppm.* Calcium hardness should be tested at least monthly. The PoolPro PS9 Titration Kit features an in-cell conductometric titration for determining hardness.
Total Dissolved Solids (TDS) is the sum of all solids dissolved in water. If all the water in a swimming pool was allowed to evaporate, TDS would be what was left on the bottom of the pool – like the white deposits left in a boiling pot after all the water has evaporated. Some of this dissolved material includes hardness, alkalinity, cyanuric acid, chlorides, bromides, and algaecides. TDS also includes bather wastes, such as perspiration, urine, and others. TDS is often confused with Total Suspended Solids (TSS). But TDS has no bearing on the turbidity, or cloudiness, of the water, as all the solids are truly in solution. It is TSS, or undissolved, suspended solids, present in or that precipitate out of the water that make the water cloudy.
High TDS levels do affect chlorine efficiency, algae growth, and aggressive water, but only minimally. TDS levels have the greatest bearing on bather comfort and water taste – a critical concern for commercial pool operators. At levels of over 5,000 ppm, people can taste it. At over 10,000 ppm bather towels are scratchy and mineral salts accumulate around the pool and equipment. Still some seawater pools comfortably operate with TDS levels of 32,000 ppm or more.
As methods of sanitization have changed, high TDS levels have become more and more of a problem. The best course of action is to monitor and control TDS by measuring levels and periodically draining and replacing some of your mature water with new, lower TDS tap water. This is a better option than waiting until you must drain and refill your pool, which is not allowed in some areas where water conservation is required by law. However, you can also decrease TDS with desalinization equipment as long as you compensate with Calcium Hardness. (Do not adjust water balance by moving pH beyond 7.8.)*
Regardless, you do need to measure and compensate for TDS to get the most precise saturation index and adjust your pH and Calcium Hardness levels accordingly. It is generally recommended that you adjust for TDS levels by subtracting one tenth of a saturation index unit (.1) for every 1,000 ppm TDS over 1,000 to keep your water properly balanced. When TDS levels exceed 5,000 ppm, it is recommended that you subtract half of a tenth, or one twentieth of unit (.05) per 1,000 ppm.* And as the TDS approaches that of seawater, the effect is negligible.
Hot tubs and spas have a more significant problem with TDS levels than pools. Because the bather load is relatively higher, more chemicals are added for superchlorination and sudsing along with a higher concentration of bather wastes. The increased electrical conductance that high TDS water promotes can also result in electrolysis or galvanic corrosion. Every hot water pool operator should consider a TDS analyzer as a standard piece of equipment.
A TDS analyzer is required to balance the water of any pool or spa in the most precise way. PoolPro, PoolMeter and ULTRAPEN PT1 instantly display accurate TDS levels giving you the information you need to take corrective action before TDS gets out of hand.
Temperature is the last and least significant factor in maintaining water balance. As temperature increases, the water balance tends to become more basic and scale- producing. Calcium carbonate becomes less soluble, causing it to precipitate out of solution. As temperature drops, water becomes more corrosive.
In addition to helping determine water balance, temperature also affects bather comfort, evaporation, chlorination, and algae growth (warmer temperatures encourage growth). Myron L’s PooLPRo also precisely measures temperature to one tenth of a degree at the same time any other parameter is measured.
In the pool and spa industry water balance is calculated using the Langelier Saturation Index (LSI) formula:
SI = (pH + TF + CF + AF ) – 12.1
PH = pH value
TF = 0.0117 x Temperature value – 0.4116 CF = 0.4341 x ln(Hardness value) – 0.3926 AF = 0.4341 x ln(Alkalinity value) – 0.0074
The following is a general industry guideline for interpreting LSI values:
• An index between -0.5 and +0.5 is acceptable pool water.
- An index of more than +0.5 is scale-forming.
- An index below -0.5 is corrosive.
pH, Total Alkalinity, and Calcium Hardness are the largest contributors to water balance. Pool water will often be balanced if these factors are kept within the recommended ranges.
The PoolPro PS9 Titration Kit features an LSI function that steps you through alkalinity & hardness titrations and pH & temperature measurements to quickly and accurately determine LSI. An LSI calculator allows you to manipulate pH, alkalinity, hardness and temperature values in the equation to determine water balance adjustments on the spot.
The most immediate concern of anyone monitoring and maintaining a pool is the effectiveness of the sanitizer – the germ-killer. There are many types of sanitizers, the most common being chlorine in swimming pools and bromine in hot tubs and spas. The effectiveness of the sanitizer is directly related to the pH and, to a lesser degree, the other factors influencing water balance.
To have true chemical control, you need to monitor both the sanitizer residual and the pH and use that information to chemically treat the water. To check chlorine residual, free chlorine measurements are made. For automatic chlorine dosing systems, ORP must also be monitored to ensure proper functioning.
Free Chlorine is the amount of chlorine available as hypochlorous acid (HOCl-) and hypochlorite ion (OCl-), the concentrations of which are directly dependent on pH and temperature. pH is maintained at the level of greatest concentration of HOCl- because hypochlorous acid is a much more powerful sanitizer than hypochlorite ion. Free chlorine testing is usually required before and after opening of commercial pools. Samples should be taken at various locations to ensure even distribution. Residual levels are generally kept between 1-2 mg/L or ppm.* PooLPRo V.4.03 and later features the ability to measure ppm free chlorine in pools and spas sanitized by chlorine only. With this feature PoolPro can measure a dynamic range of chlorine concentrations wider than that of a colorimetric test kit with a greater degree of accuracy.
ORP stands for Oxidation Reduction Potential (or REDOX ) of the water and is measured in millivolts (mV). The higher the ORP, the greater the killing power of all sanitizers, not just free chlorine, in the water. ORP is the only practical method available to monitor sanitizer effectiveness. Thus, every true system of automatic chemical control depends on ORP to work.
The required ORP for disinfection will vary slightly between disinfecting systems and is also dependent on the basic water supply potential, which must be assessed and taken into account when the control system is initialized. 650 mV to 700 – 750 mV is generally considered ideal.*
Electronic controllers can be inaccurate and inconsistent when confronted with certain unique water qualities, so it is critical to perform manual testing with separate instrumentation. For automatic control dosing, it is generally recommended that you manually test pH and ORP prior to opening and then once during the day to confirm automatic readings.*
Samples for confirming automatic control dosing should be taken from a sample tap strategically located on the return line as close as possible to the probes in accordance with the manufacturer’s instructions. If manual and automatic readings consistently move further apart or closer together, you should investigate the reason for the difference.*
ORP readings can only be obtained with an electronic instrument. PoolPro provides the fastest, most precise, easy-to-use method of obtaining ORP readings to check the effectiveness of the sanitizer in any pool or spa. This is the best way to determine how safe your water is at any given moment.
A relatively new development, saltwater pools use regular salt, sodium chloride, to form chlorine with an electrical current much in the same way liquid bleach is made. As chlorine – the sanitizer – is made from the salt in the water, it is critical to maintain the salt concentration at the appropriate levels to produce an adequate level of sanitizer. It is even more important to test water parameters frequently in these types of pools and spas, as saltwater does not have the ability to respond adequately to shock loadings (superchlorination treatments).
Most saltwater chlorinators require a 2,500 – 3,000 ppm salt concentration in the water (though some may require as high as 5,000-7,000 ppm).* This can barely be tasted, but provides enough salt for the system to produce the chlorine needed to sanitize the water.
(It is important to have a good stabilizer level – 30 – 50 ppm* – in the pool, or the sunlight will burn up the chlorine. Without it, the saltwater system may not be able to keep up with the demand regardless of salt concentration.)
Taste and salt shortages are of little concern to seawater systems that maintain an average of 32,000 ppm. In these high-salt environments, you need to beware of corrosion to system components that can distort salt level and other parameter readings.
Additionally, incorrect salt concentration readings can occur in any saltwater system. The monitoring/controlling components can and do fail or become scaled— sometimes giving a false low salt reading. Thus, you must test manually for salt concentration with separate instrumentation before adding salt.
You must also test salt concentration manually with separate instrumentation to re-calibrate your system. This is critical to system functioning and production of required chlorine. Both the PoolPro and PT1 conveniently test for salt concentration at the press of a button as a check against automatic controller systems that may have disabled equipment or need to be re-calibrated.
Though no one instrument or method can be used to determine ALL of the factors that affect the comfort and sanitation of pool and spa water, PoolPro is a comprehensive water testing instrument that is reliable durable, easy-to-use and easy-to-maintain and calibrate. As a pool professional, a PoolPro will not only simplify your life, it will save you time and money.
RECORD KEEPING – WHAT TO DO WITH ALL THOSE MEASUREMENTS …
Data handling should be done objectively, and data recorded in a common format in the most accurate way. Also, data should be stored in more than one permanent location and made available for future analysis. Most municipalities require commercial aquatic facilities to keep permanent records on site and available for inspection at any time.
PoolPro makes it easy to comply with record keeping requirements. The PoolPro is an objective means to test free chlorine, ORP, pH, TDS, temperature and the mineral/salt content of any pool or spa. You just rinse and fill the cell cup by submerging the waterproof unit and press the button of the parameter you wish to measure. You immediately get a standard, numerical digital readout – no interpretation required – eliminating all subjectivity. And model PS9TK features the added ability to perform in-cell conductometric titrations for Alkalinity, Hardness and LSI on the spot. Up to 100 date-time-stamped readings can be stored in memory and then later transferred directly to a computer wirelessly using the bluDock™ accessory package. Simply pair the bluDock with your computer, then open the U2CI software application to download data. The user never touches the data, reducing the potential for human error in transcription. The data can then be imported into any program necessary for record-keeping and analysis. The bluDock is a quick and easy way to keep records that comply with governing standards.*
*Consult your governing bodies for specific testing, chemical concentrations, and all other guidelines and requirements. The ranges and methods suggested here are meant as general examples.
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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
TweetA TDS Meter indicates the Total Dissolved Solids (TDS) of a solution (the concentration of dissolved solids in it). Since dissolved ionized solids such as salts and minerals increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that. Dissolved organic solids such as sugar […]
A TDS Meter indicates the Total Dissolved Solids (TDS) of a solution (the concentration of dissolved solids in it). Since dissolved ionized solids such as salts and minerals increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that.
Dissolved organic solids such as sugar and colloids don’t affect the conductivity of a solution much so a TDS meter does not include them in its reading.
Units of TDS
A TDS meter usually displays TDS in parts per million (ppm). For example, a TDS reading of 1 ppm would indicate there is 1 milligram of dissolved solids in each kilogram of water.
The two chief methods of measuring total dissolved solids are gravimetry and conductivity. Gravimetric methods are the most accurate and involve evaporating the liquid solvent and measuring the mass of residues left. This method is generally the best but time-consuming. If inorganic salts comprise the majority of TDS, gravimetric methods are recommended.
Electrical conductivity of water is directly related to the concentration of dissolved ionized solids in the water. Ions from the dissolved solids in water create the water’s ability to conduct an electrical current, which can be measured using a conventional conductivity meter or TDS meter. When correlated with laboratory TDS measurements, conductivity provides an approximate value for the TDS concentration.
Total Dissolved Solids (TDS) is a measure of the combined content of all inorganic and organic substances contained in a liquid in: molecular, ionized or micro-granular (colloidal sol) suspended form. The operational definition is that the solids must be small enough to survive filtration through a two micrometer sieve. Total dissolved solids are normally discussed only for freshwater systems, as salinity comprises some of the ions constituting the definition of TDS. The principal application of TDS is in the study of water quality for streams, rivers and lakes, although TDS is not generally considered a primary pollutant (e.g. it is not deemed to be associated with health effects) it is used as an indication of aesthetic characteristics of drinking water and as an aggregate indicator of the presence of a broad array of chemical contaminants.
Primary sources for TDS in receiving waters are agricultural and residential runoff, leaching of soil contamination and point source water pollution discharge from industrial or sewage treatment plants. The most common chemical constituents are calcium, phosphates, nitrates, sodium, potassium and chloride, which are found in nutrient runoff, storm water runoff and runoff from snowy climates where road de-icing salts are applied. The chemicals may be cations, anions, molecules or agglomerations on the order of one thousand or fewer molecules, so long as a soluble micro-granule is formed. More exotic and harmful elements of TDS are pesticides arising from surface runoff. Certain naturally occurring total dissolved solids arise from the weathering and dissolution of rocks and soils. The United States has established a secondary water quality standard of 500 mg/l to provide for palatability of drinking water.
TDS Measurement Applications
High TDS levels indicate hard water, which can cause scale buildup in pipes, valves, and filters, reducing performance and adding to system maintenance costs. These effects can be seen in aquariums, spas, swimming pools, and reverse osmosis water treatment systems. Typically, in these applications, total dissolved solids are tested frequently, and filtration membranes are checked in order to prevent adverse effects.
In the case of hydroponics and aquaculture, TDS is often monitored in order to create a water quality environment favorable for organism productivity. For freshwater oysters, trouts, and other high value seafood, highest productivity and economic returns are achieved by mimicking the TDS and pH levels of each species’ native environment. For hydroponic uses, TDS is considered one of the best indices of nutrient availability for the aquatic plants being grown.
Because the threshold of acceptable aesthetic criteria for human drinking water is 500 mg/l, there is no general concern for odor, taste, and color at a level much lower than is required for harm. A number of studies have been conducted and indicate various species’ reactions range from intolerance to outright toxicity due to elevated TDS. The numerical results must be interpreted cautiously, as true toxicity outcomes will relate to specific chemical constituents. Nevertheless, some numerical information is a useful guide to the nature of risks in exposing aquatic organisms or terrestrial animals to high TDS levels. Most aquatic ecosystems involving mixed fish fauna can tolerate TDS levels of 1000 mg/l.
Boilers & cooling towers, Deionization, Reverse osmosis, Chemical concentrations, Printing fountain solutions, Swimming pools & spas, Water pollution control, Wastewater & more…
Myron L Meters Top-selling TDS Meters
ULTRAPEN PT1 Conductivity – TDS – Salinity Pen
Accuracy of +/-1% of READING (+/-.2% at Calibration Point)
Reliable Repeatable Results
Solution modes: KCl, NaCl and 442
Automatic Temperature Compensation
Durable, Fully Potted Circuitry
EP-10: 0-10, 100, 1000, 10,000 micromhos/microsiemens
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
Multi-Parameter: Conductivity, TDS, Resistivity, Temperature
+/-1% Accuracy of Reading
Memory Storage: Save up to 100 samples w/ Date & Time stamp
Wireless Download Module Optional
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TweetThe conductivity (or specific conductance) of a solution is a measure of its ability to conduct electricity. The standard unit of conductivity is siemens per meter (S/m). Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring ionic content in a solution. For example, the […]
The conductivity (or specific conductance) of a solution is a measure of its ability to conduct electricity. The standard unit of conductivity is siemens per meter (S/m).
Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems.
In many cases, conductivity is linked directly to the total dissolved solids (TDS). High quality deionized water has a conductivity of about 5.5 μS/m, typical drinking water in the range of 5-50 mS/m, while sea water about 5 S/m (i.e., sea water’s conductivity is one million times higher than deionized water).
Conductivity is traditionally determined by measuring the AC resistance of the solution between two electrodes.
Resistivity of pure water (in MΩ-cm) as a function of temperature
The standard unit of conductivity is S/m and usually refers to 25 °C (standard temperature). Often encountered in industry is the traditional unit of μS/cm. 106 μS/cm = 103 mS/cm = 1 S/cm. The numbers in μS/cm are higher than those in μS/m by a factor of 100 (i.e., 1 μS/cm = 100 μS/m). Occasionally a unit of “EC” (electrical conductivity) is found on scales of instruments: 1 EC = 1 μS/cm. Sometimes encountered is a so-called mho (reciprocal of ohm): 1 mho/m = 1 S/m. Historically, mhos antedate Siemens by many decades; good vacuum-tube testers, for instance, gave transconductance readings in micromhos.
The commonly used standard cell has a width of 1 cm, and thus for very pure water in equilibrium with air would have a resistance of about 106 ohm, known as a megohm. Ultra-pure water could achieve 18 megohms or more. Thus in the past megohm-cm was used, sometimes abbreviated to “megohm”. Sometimes conductivity is given just in “microSiemens” (omitting the distance term in the unit). While this is an error, it’s usually assumed to be equal to the traditional μS/cm. The typical conversion of conductivity to the total dissolved solids is done assuming that the solid is sodium chloride: 1 μS/cm is then an equivalent of about 0.6 mg of NaCl per kg of water.
A conductivity meter and probe
The electrical conductivity of a solution is measured by determining the resistance of the solution between two flat or cylindrical electrodes separated by a fixed distance. An alternating voltage is used in order to avoid electrolysis. The resistance is measured by a conductivity meter. Typical frequencies used are in the range 1–3 kHz. The dependence on the frequency is usually small, but may become appreciable at very high frequencies, an effect known as the Debye–Falkenhagen effect.
A wide variety of instrumentation is commercially available. There are two types of cell, the classical type with flat or cylindrical electrodes and a second type based on induction. Many commercial systems, Myron L meters, e.g., offer automatic temperature correction.
MyronLMeters.com offers many reliable conductivity meters – some analog, some digital, some pen-style, some multiparameter – but all accurate, reliable, and easy-to-use.
512M5: 0-5000 micromhos/microsiemens
Instant and accurate Conductivity tests
Electronic Internal Standard for easy field calibration
Fast Auto Temperature Compensation
Rugged design for years of trouble-free testing
Simple to use
ULTRAPEN PT1 Conductivity – TDS – Salinity Pen
Accuracy of +/-1% of READING (+/-.2% at Calibration Point)
Reliable Repeatable Results
Solution modes: KCl, NaCl and 442
Automatic Temperature Compensation
Durable, Fully Potted Circuitry
Digital Handheld Multi-Parameter meter: 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
The unique circuitry of our 750 Series II Conductivity Inline Meters guarantees accurate and reliable measurements. Drift-free performance is assured by “field proven” electronics, including automatic DC offset compensation and highly accurate drive voltage.
Since Temperature Compensation is at the heart of accurate water measurement, all Myron L Monitor/controllers feature a highly refined and precise TC circuit. This feature perfectly matches the water temperature coefficient as it changes. All models are corrected to 25′C. The TC may be disabled to conform to USP requirements.
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 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, 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 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 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 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.
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 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 (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 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.
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.
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
Tweet Myron L Meters thanks Dalscorp engineering consultants of Brunswick, Maine, proud owners of a new Ultrapen PT1 conductivity/TDS/salinity pen. ULTRAPEN PT1 Conductivity/TDS/Salinity Pen. This instrument is designed to be extremely accurate, fast and simple to use in diverse water quality applications. Advanced features include the ability to select from 3 different solution types that […]
Myron L Meters thanks Dalscorp engineering consultants of Brunswick, Maine, proud owners of a new Ultrapen PT1 conductivity/TDS/salinity pen.
TweetMyronLMeters.com today announced the imminent release of a new Myron L product, the Myron L Ultrapen PT1, a reliable, easy-to-use pen-style meter that measures 3 parameters – conductivity, TDS, and salinity. FOR IMMEDIATE RELEASE San Diego, California, United States of America(Free-Press-Release.com) February 27, 2011 – MyronLMeters.com today announced the arrival of a new Myron L product, the […]
MyronLMeters.com today announced the imminent release of a new Myron L product, the Myron L Ultrapen PT1, a reliable, easy-to-use pen-style meter that measures 3 parameters – conductivity, TDS, and salinity.
FOR IMMEDIATE RELEASE
MyronLMeters.com today announced the arrival of a new Myron L product, the Myron L Ultrapen PT1, a reliable, easy-to-use pen-style meter that measures 3 parameters – conductivity, TDS, and salinity.
“The Myron L Ultrapen PT1 will be available soon
at MyronLMeters.com,” said James Rutan, president, “and it’s going to be a great seller. The Pocket Tester’s convenience, durability, accuracy, and reliability are unmatched in the industry. It comes complete with a battery installed (and an extra), holster, lanyard, scoop, and instructions. The Myron L PT1 is waterproof, has fully secured circuitry and, as always, MyronLMeters.com has made it easy to order. At MyronLMeters.com, you get a 10% discount…just for ordering online. In addition, all Myron L meters in stock will ship the next business day. The quality of the Ultrapen PT1 and the company’s great reputation for reliable meters is sure to make this a big hit. It even looks great!”
Myron L meters are renowned for their accuracy, reliability, and ease of use, and have applications in automatic rinse tank controls, boiler and cooling towers, circuit board cleanliness testing, deionized water, environmental applications, fountain solutions, dialysis, horticulture, hydroponics, ORP (oxidation reduction potential)/Redox, pool and spa, reverse osmosis, textiles.
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More at http://www.myronlmeters.com
TweetConductivity is the ability of a material to transmit energy in the form of electricity or heat. In water quality terms, it indicates how much conductive material is in the water. The higher the conductivity measurement, the more conductive material is in the water. The standard unit of measure for conductivity is Siemens per meter […]
Conductivity is the ability of a material to transmit energy in the form of electricity or heat. In water quality terms, it indicates how much conductive material is in the water. The higher the conductivity measurement, the more conductive material is in the water.
The standard unit of measure for conductivity is Siemens per meter (S/m).
The siemens (symbol: S) is a unit of electric conductance and electric admittance. Conductance and admittance are the reciprocals of resistance and impedance respectively, hence one siemens is equal to the reciprocal of one ohm, and is sometimes referred to as the mho. It is named after the German inventor and industrialist Ernst Werner von Siemens. In English, the term siemens is used both for the singular and plural.
When testing water quality for conductivity measurements, you will hear terms like microsiemens, micromhos, millisiemens, and millimhos.
-Microsiemens (uS) is the same as the micromhos (umhos).
-Millisiemens (mS) is the same as millimhos (mmhos).
These units of measure operate the same way as metric distance measures. The meter is short and the kilometer is long, but they both measure distance. Microsiemens and millisiemens work the same way. 1 millisiemen is equal to 1000 microsiemens.
Different materials conduct electricity differently – this principle applies to dissolved materials, as well. If you have a tablespoon of sodium chloride (table salt) and dump it in a glass of pure water, then take another tablespoon of potassium chloride salts and dump it in another glass of pure water, the conductivity measurements from the two glasses will be different.
Some typical conductivity measurements of water:
Ultra pure water: 0.05 – 1.0 microsiemens
Drinking water: 200 – 500 microsiemens
Seawater: 30,000 – 50,000 microsiemens
It is important to use a conductivity meter that can test different salt types and properly compensate for temperature differences in order to get the most accurate conductivity measurements.
To learn about Conductivity vs. TDS, check out this blog post: http://blog.myronlmeters.com/archive/5