TweetContamination of circuit boards can bring about severe degradation of insulation resistance and dielectric strength. Cleanliness of completed circuit boards is, therefore, of vital interest. For those companies who have established circuit board cleaning procedures, the MIL Spec P-28809 has been used as a guideline for control. Now a simple “on line” test for the [...]
Contamination of circuit boards can bring about severe degradation of insulation resistance and dielectric strength. Cleanliness of completed circuit boards is, therefore, of vital interest.
For those companies who have established circuit board cleaning procedures, the MIL Spec P-28809 has been used as a guideline for control. Now a simple “on line” test for the relative measurement of ionic contamination has been developed.
This fast and economical method for testing circuit board cleanliness uses an Ultrameter II™ 4P or 6P, a suitable container, and a mixture of Dl (deionized) water and alcohol. The procedure is as follows:
1. Mix a stock quantity of solution using 25 parts by volume of Dl water and 75 parts by volume of 99% isopropyl alcohol. The conductivity, measured with the Ultrameter II 4P or 6P should be a maximum of 0.166 micromhos/microseimens/cm.
2. Measure out an amount of the water/alcohol mixture equal to 100 ml per 10 square inches of circuit board surface to be tested (considering both sides of the board but not components), and add 60 ml additional. In other words: 2(L X W) (10 ml) + 60 ml = total solution needed.
3. Fill a poly “zip-lock” bag or other suitable plastic or glass container with the measured water/alcohol solution.
4. Using the measured water/alcohol solution in the poly bag, rinse out the Ultrameter II’s cell cup three (3) times, discarding the rinse solution each time. Fill the instrument cell cup a fourth time and take a meter reading. This value should be 0.166 micromhos/microseimens/cm or less and is the very clean control (or “comparison”) reading for the test.
5. Being very careful not to contaminate the PCB, totally immerse the circuit board in the solution. Seal bag. Allow it to soak for three (3) minutes with mild agitation.
6. At the conclusion of the soaking, pour the solution directly into the instruments cell cup four (4) times; take the fourth reading.
7. Compare the control reading in Step 4 with the reading taken in Step 6 (The higher the difference between the two readings, the greater the ionic contamination). Record this final extract reading for comparison with other boards tested in the same manner.
The level of cleanliness needed can be determined by each individual company.
Mil Spec P-28809 can be used as a guideline, or standards can be established based upon available data. In either event, the comparative method using the Myron L Ultrameter II will assist in the determination of that level of cleanliness.
TweetProper rinsing is one of the most important steps in quality manufacturing or metal finishing. Plenty of low cost, good quality water for rinsing has been available in the past, so rinse water conservation has been largely ignored. Today, this is no longer true. Tap water costs have increased dramatically. Various new regulations are now [...]
Proper rinsing is one of the most important steps in quality manufacturing or metal finishing. Plenty of low cost, good quality water for rinsing has been available in the past, so rinse water conservation has been largely ignored.
Today, this is no longer true. Tap water costs have increased dramatically. Various new regulations are now in effect which limit the allowable volume of wastewater. Others require wastewater treatment. Still other laws tax the amount of water going down the sewer.
These factors have all encouraged many manufacturers and platers to invest in automatic rinse tank control systems. Many platers using automatic control systems for the first time are pleased to discover a reduction in water usage of up to 80%.
This water use reduction provides two major benefits:
1. LOWER WATER BILLS
The savings possible with Myron L automatic Rinse Tank CONTROLSTIK II™ Systems are illustrated in the following table. Figures are based on a 50% water reduction rate; the minimum that can usually be expected. Exact savings depend on several variables, including the type and frequency of workloads, rinse tank size, and type of contaminant.
NOTE: 100 cubic feet of water is equivalent to 2831.5 liters/748 gallons.
2. WASTE TREATMENT SYSTEM INVESTMENT IS REDUCED.
The second major cost advantage of the CONTROLSTIK II™ System: Reducing the investment required for waste treatment equipment. Because less water is handled, smaller capacity treatment/recovery systems can be used to meet government water pollution regulations.
Generally, chemicals being “dragged in” and salts that are dissolved from work being rinsed cause rinse water contamination. These solutions ionize and can be measured and controlled by Electrical Conductivity (EC). EC measures both the total dissolved solids and the non-solid (eg: acid) contaminants, thereby giving the most correct method of control. As water contamination increases, so does the conductivity; the automatic rinse tank controls operate on this principle. When conductivity reaches the value selected as a control point, the water valve turns on to dilute the contamination. When the contaminants are reduced by the dilution, the conductivity falls and the water valve turns off.
The unit of measurement for conductivity is the micromhos (microseimens); Myron L systems are calibrated to this unit. All Myron L Rinse Tank CONTROLSTIK II Systems can be used in either normal tap water or in Deionized (DI) water tanks. The dual range sensor can be set on either the 5-500 or the 500-5000 micromhos range. The AUTOMATIC RINSE TANK CONTROL is briefly described below. All Myron L CONTROLSTIK II Systems consist of three components: Transformer Box, CONTROLSTIK Sensor, and Solenoid Valve.
AUTOMATIC RINSE TANK MODEL
Reliable solid-state electronics in a heavy-duty, IP65/NEMA 4X Corrosion and water resistant transformer box enclosure, suitable for any plating environment.
OTHER PRODUCTS USEFUL FOR FINISHING APPLICATIONS
Also available are hand-held Conductivity & pH Instruments for “on-the-spot” water quality testing. The Conductivity and pH sensors are built in for maximum protection. The pH sensor is user replaceable. 750 Series II Monitor/controllers for continuous in-line water quality monitoring. For additional information, please refer to Myron L data sheets, or Ask An Expert at MyronLMeters.com.
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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.
TweetYears ago, high purity water was used only in limited applications. Today, deionized (Dl) water has become an essential ingredient in hundreds of applications including: medical, laboratory, pharmaceutical, cosmetics, electronics manufacturing, food processing, plating, countless industrial processes, and even the final rinse at the local car wash. THE DEIONIZATION PROCESS The vast majority of dissolved [...]
Years ago, high purity water was used only in limited applications. Today, deionized (Dl) water has become an essential ingredient in hundreds of applications including: medical, laboratory, pharmaceutical, cosmetics, electronics manufacturing, food processing, plating, countless industrial processes, and even the final rinse at the local car wash.
THE DEIONIZATION PROCESS
The vast majority of dissolved impurities in modern water supplies are ions such as calcium, sodium, chlorides, etc. The deionization process removes ions from water via ion exchange. Positively charged ions (cations) and negatively charged ions (anions) are exchanged for hydrogen (H+) and hydroxyl (OH-) ions, respectively, due to the resin’s greater affinity for other ions. The ion exchange process occurs on the binding sites of the resin beads. Once depleted of exchange capacity, the resin bed is regenerated with concentrated acid and caustic which strips away accumulated ions through physical displacement, leaving hydrogen or hydroxyl ions in their place.
Deionizers exist in four basic forms: disposable cartridges, portable exchange tanks, automatic units, and continuous units. A two-bed system employs separate cation and anion resin beds. Mixed-bed deionizers utilize both resins in the same vessel. The highest quality water is produced by mixed-bed deionizers, while two-bed deionizers have a larger capacity. Continuous deionizers, mainly used in labs for polishing, do not require regeneration.
TESTING Dl WATER QUALITY
Water quality from deionizers varies with the type of resins used, feed water quality, flow, efficiency of regeneration, remaining capacity, etc. Because of these variables, it is critical in many Dl water applications to know the precise quality. Resistivity/ conductivity is the most convenient method for testing Dl water quality. Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohm) and conductivity of 0.055 microsiemens. It is the amount of ionized substances (or salts) dissolved in the water which determines water’s ability to conduct electricity. Therefore, resistivity and its inverse, conductivity, are good general purpose quality parameters.
Because temperature dramatically affects the conductivity of water, conductivity measurements are internationally referenced to 25°C to allow for comparisons of different samples. With typical water supplies, temperature changes the conductivity an average of 2%/°C, which is relatively easy to compensate. Deionized water, however, is much more challenging to accurately measure since temperature effects can approach
10%/°C! Accurate automatic temperature compensation, therefore, is the “heart’ of any respectable instrument.
Portable instruments are typically used to measure Dl water quality at points of use, pinpoint problems in a Dl system confirm monitor readings, and test the feed water to the system. The handheld Myron L meters have been the first choice of Dl water professionals for many years. For two-bed Dl systems, there are several usable models with displays in either microsiemens or ppm (parts per million) of total dissolved solids. The most versatile instruments for Dl water is the 4P or 6P Ultrameter II™, which can measure both ultrapure mixed- bed quality water and unpurified water. It should be noted that once Dl water leaves the piping, its resistivity will drop because the water absorbs dissolved carbon dioxide from the air. Measuring of ultrapure water with a hand-held instrument requires not only the right instrument, but the right technique to obtain accurate, repeatable readings. Myron L meters offer the accuracy and precision necessary for ultrapure water measurements.
In-line Monitor/controllers are generally used in the more demanding Dl water applications. Increased accuracy is realized since the degrading effect of carbon dioxide on high purity water is avoided by use of an in-line sensor (cell). This same degradation of ultrapure water is the reason there are no resistivity calibration standard solutions (as with conductivity instruments). Electronic sensor substitutes are normally used to calibrate resistivity Monitor/controllers.
Myron L manufactures a variety of in-line instruments, including resistivity Monitor/controllers which are designed specifically for Dl water. Seven resistivity ranges are available to suit any Dl water application: 0-20 megohm, 0-10 megohm,
0-5 megohm, 0-2 megohm, 0-1 megohm, 0-500 kilohm, and 0-200 kilohm. Temperature compensation is automatic and achieved via a dual thermistor circuit. Monitor/controller models contain an internal adjustable set point, Piezo alarm connectors and a heavy-duty 10 amp relay circuit which can be used to control an alarm, valves, pump, etc. Available options include 4-20 milliamp output, 3 sensor input, 3 range capability and temperature. Internal electronic sensor substitutes are standard on all Monitor/controllers.
Sensors are available constructed in either 316 stainless steel or titanium. All sensors are provided with a 3/4″ MNPT polypropylene bushing and 10 ft./3 meters of cable. Optional PVDF or stainless steel bushings can be ordered, as well as longer cable lengths up to 100 ft./30 meters.
For details and recommendations, please refer to Myron L data sheets, visit our website (www.myronlmeters.com), or contact us by email (email@example.com).
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 [...]
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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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.
The United States has the most comprehensive system of assistance for veterans of any nation in the world. This benefits system traces its roots back to 1636, when the Pilgrims of Plymouth Colony were at war with the Pequot Indians. The Pilgrims passed a law which stated that disabled soldiers would be supported by the colony.
The Continental Congress of 1776 encouraged enlistments during the Revolutionary War by providing pensions for soldiers who were disabled. Direct medical and hospital care given to veterans in the early days of the Republic was provided by the individual States and communities. In 1811, the first domiciliary and medical facility for veterans was authorized by the Federal Government. In the 19th century, the Nation’s veterans assistance program was expanded to include benefits and pensions not only for veterans, but also their widows and dependents.
After the Civil War, many State veterans homes were established. Since domiciliary care was available at all State veterans homes, incidental medical and hospital treatment was provided for all injuries and diseases, whether or not of service origin. Indigent and disabled veterans of the Civil War, Indian Wars, Spanish-American War, and Mexican Border period as well as discharged regular members of the Armed Forces were cared for at these homes.
Congress established a new system of veterans benefits when the United States entered World War I in 1917. Included were programs for disability compensation, insurance for service persons and veterans, and vocational rehabilitation for the disabled. By the 1920s, the various benefits were administered by three different Federal agencies: the Veterans Bureau, the Bureau of Pensions of the Interior Department, and the National Home for Disabled Volunteer Soldiers.
The establishment of the Veterans Administration came in 1930 when Congress authorized the President to “consolidate and coordinate Government activities affecting war veterans.” The three component agencies became bureaus within the Veterans Administration. Brigadier General Frank T. Hines, who directed the Veterans Bureau for seven years, was named as the first Administrator of Veterans Affairs, a job he held until 1945.
The VA health care system has grown from 54 hospitals in 1930, to include 152 hospitals; 800 community based outpatient clinics; 126 nursing home care units; and 35 domiciliaries. VA health care facilities provide a broad spectrum of medical, surgical, and rehabilitative care. The responsibilities and benefits programs of the Veterans Administration grew enormously during the following six decades. World War II resulted in not only a vast increase in the veteran population, but also in large number of new benefits enacted by the Congress for veterans of the war. The World War II GI Bill, signed into law on June 22, 1944, is said to have had more impact on the American way of life than any law since the Homestead Act of 1862. Further educational assistance acts were passed for the benefit of veterans of the Korean Conflict, the Vietnam Era, Persian Gulf War, Iraq and Afghanistan wars.
In 1973, the Veterans Administration assumed another major responsibility when the National Cemetery System (except for Arlington National Cemetery) was transferred to the Veterans Administration from the Department of the Army. The Agency was charged with the operation of the National Cemetery System, including the marking of graves of all persons in national and State cemeteries (and the graves of veterans in private cemeteries, upon request) as well and administering the State Cemetery Grants Program. The Department of Veterans Affairs (VA) was established as a Cabinet-level position on March 15, 1989. President Bush hailed the creation of the new Department saying, “There is only one place for the veterans of America, in the Cabinet Room, at the table with the President of the United States of America.”
In 2009, President Obama appointed Secretary Eric K. Shinseki to lead a massive transformation of the VA into a high-performing 21st century organization that can better serve Veterans. Under the leadership of Secretary Shinseki, the VA has adopted three guiding principles to govern the changes underway, namely being people-centric, results-driven, and forward-looking. These principles are reflected in the 16 major initiatives that serve as a platform from which transformation is being executed.
The 16 major initiatives are:
Eliminating Veteran homelessness
Enabling 21st century benefits delivery and services
Automating GI Bill benefits
Creating Virtual Lifetime Electronic Record
Improving Veterans’ mental health
Building Veterans Relationship Management capability to enable convenient, seamless interactions
Designing a Veteran-centric health care model to help Veterans navigate the health care delivery system and receive coordinated care
Enhancing the Veteran experience and access to health care
Ensuring preparedness to meet emergent national needs
Developing capabilities and enabling systems to drive performance and outcomes.
Establishing strong VA management infrastructure and integrated operating model
Transforming human capital management
Performing research and development to enhance the long-term health and well-being of Veterans
Optimizing the utilization of VA’s Capital portfolio by implementing and executing the Strategic Capital Investment Planning (SCIP) process
Improving the quality of health care while reducing cost
Transforming health care delivery through health informatics
Myron L Meters is proud to do business with the VA.
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Tweet Myron L Meters thanks the U.S. Navy Trident Refit Facility, owners of a new Myron L Ultrameter III 9P. Learn more about their fine unit here: http://blog.myronlmeters.com/archives/290 There’s always more at MyronLMeters.com.
Tweet MyronLMeters.com is proud to do business with Better Baked Foods, Inc. You can find out more about this fine company at http://www.betterbaked.com. For more than 40 years, Better Baked Foods has been a leader in developing new ideas in the frozen foods market. An expert in frozen food manufacturing, Better Baked Foods develops [...]
MyronLMeters.com is proud to do business with Better Baked Foods, Inc. You can find out more about this fine company at http://www.betterbaked.com.
Tweet http://www.sciencedaily.com/releases/2011/03/110310070455.htm ScienceDaily (2011-03-10) — Researchers in Spain have developed an irrigation telecontrol system which will enable saving up to 20 percent of water for each harvest, compared to traditional irrigation methods. More at http://www.blog.MyronLMeters.com
ScienceDaily (2011-03-10) — Researchers in Spain have developed an irrigation telecontrol system which will enable saving up to 20 percent of water for each harvest, compared to traditional irrigation methods.
More at http://www.blog.MyronLMeters.com