What is the Best Place to Live in the United States and Canada – One Almanac Tells All

During the recession many families are re-thinking where they live and considering making a move, something they take very seriously, and can not afford to make a mistake. But where do they move too? Where can they get all the information they need to make an informed decision? Well, boy have I got the perfect book to aid in this search:

"Places Rated Almanac; Your Guide to Finding the Best Places to Live in the United States and Canada" (Special Millennium Edition) by David Savageau with Ralph D'Agostino; IDG Books Worldwide, Inc., Foster City, CA; 2000.

This book is a wealth of information on places to live, listed are some 354 Metro Areas which are ranked by crime, weather, arts, recreation, sports teams, job base, education, transportation, energy, pollution, cost of living and health care considerations. There is so much data in this book that you will be blown away, and it will make you consider things you may not have ever thought about before, such as the number of restaurants, churches, or parks. How about bike lanes, traffic times, yep, all listed.

How about good paying jobs? Cost of homes, rentals or business locations? Rainy days, sunny days, cloudy days, stormy days, well, it is all here in one great almanac book and you can cross reference to your heart's content. All the suburbs are listed and the driving times to town, as well as trains, buses, subways, light rail, airports, number of airlines, it's a demographic dream come true, perfect for business or just plain deciding where to live and hang your hat, raise your family or retire to.


Evaluating The Nursing Assistant Salary

If you want to start a new career in health care profession in less time then certified nursing training is the right choice for you. The training is for a short period and then you will be writing an exam for the certification. Once you are certified, you will be working as a Certified Nursing Assistant either in hospitals, nursing homes, medical centres or you will be working individually by visiting patients at their homes. You will be helping people in long term sickness, people with physically disability, and children with mental diseases. While working in hospitals, you will be supporting registered nurses with their day to day tasks and help them working on medical equipments. You will be getting lots of benefits and on top of that nursing assistant salary is also very motivational.

Talking about the training program for the nursing assistant training, the duration of the training is different in different states according to their rules. There is a standard training based on 11 modules. It takes from one month to three months to complete the training for certified nursing assistant, many schools and colleges are taking the training classes for this certification. The American Red Cross is also providing the training facilities under highly skilled and experienced educationists and medical professionals.

You can also take the certification classes online by registering yourself with various websites providing training facilities. The online training is more favourable for those people who are currently working in different professions and due to poor job stability they now want to change their profession. They can have these online classes even while they are at work and if not, they can take the classes in their spare time. There are many people who are taking the training classes online and want to start the new career in healthcare profession. The reason could be the nursing assistant salary with great career progression and job stability.

Now if you do not afford or you can pay but a small amount then there are many hospitals and nursing homes where you can take the training classes. The nursing-homes will provide you the training in the class rooms and you will be working in the medical wards helping patients with sitting, feeding and some other tasks assigned to you. This will help to get a grip on the practical side of the training. Once you have passed the exam, you will get the certification and will be offered a job by the same nursing home. Nursing assistant salary is a high scale salary and once you will start working you will be surprised by the frequent pay raise, promotions and great career advancement. The newly certified nursing assistant get pay hourly and per hour rate starts from $10 and you work for 40 hours in a week. While working in hospitals with registered nurse you will come to know that most of the registered nurses had started their career as Certified Nursing Assistant.


Steam Boilers’ Thirteen Essential Fittings in a Nutshell

Steam boiler is dangerous machinery, and for that reason, law is required to control every aspect of the boiler. Factories & Machinery (Steam Boilers and Unfired Pressure Vessel) Regulations, 1970, provided stringent requirement on safety aspects and controls on boilers. This Code stipulates that any boiler should consolidate thirteen essential fittings so that boilers can be operated safely.

The thirteen essential fittings can be grouped into three categories. The first category is safety fitting. Safety fittings include safety valves, gauge glasses, pressure gauge, low water alarm, low-water fuel cutout, and fusible plug. The second category is control fittings, which incorporate blowdown valves, main stop valve, feed check valve, and feed pumps. The final category is legal fitting, which incorporate inspector’s test attachment, registration plate, and manufacturer’s name plate. In this article, I would discuss some safety fittings.

Safety valve is the most important safety fitting on a boiler. It is fitted to prevent excessive pressure buildup in the boiler which could lead to boiler explosion. FMA Regulations 1970 stipulates that every boiler having a heating surface surpassing 100 sq.ft must be equipped with two safety valves, one of which must be direct spring-loaded type, mounted vertically as close as practical to the steam boiler shell without shut valve placed in between. The relieving capacity of safety valves is determined by the capacity of the boiler at peak load. The safety valves must be able to effectively discharge all steam with a rise of pressure of not greater than ten percent of the authorized safe working pressure (ASWP). The safety valves must be set to blow at different pressures. The first valve should open when the pressure exceeds three percent above the boiler working pressure while the other valve should open at a pressure slightly higher but must not be higher than the ASWP. The working pressure of a boiler is usually set at seven percent below ASWP. The spindles, disk, and other moving parts must not be made of materials that corrode easily.

Pressure gauge is the fitting that measures steam pressure inside the steam boiler. The Bourdon tube is the most common pressure gauge used on a boiler. The Code specifies that a pressure gauge should be installed on the steam space and provided with a shutoff cock and a siphon which develops and maintains a water seal, protecting direct contact of live steam with the Bourdon tube. A pressure gauge is usually mounted in front of the boiler in such a position that the boilermen can conveniently read it from the firing floor. FMA (Steam Boilers and Unfired Pressure Vessels) Regulations, 1970 stipulates that the diameter of the dial must not be less than 6 inches and must show pressure within a tolerance of two percent the authorized safe working pressure. The scale on the dial of a code pressure gauge must be graduated to not less than one and one-third and not more than twice ASWP.

A fusible plug is used in addition to other forms of low water protection. This device is not required by ASME code but is still included in FMA Regulations 1970. The fusible plug in watertube boiler is placed 3 inches below lowest water level while in firetube boiler, fusible plug is placed 3 inches above top tubes. In the event of low water, fusible plug will melt, the pressure inside the boiler is released, and the sound of escaping steam will produce high whistling sound, alerting the boilermen. However, the capability of fusible plug to quench the fire in the furnace is debatable because the steam rushed out is too small to have quenching impact. The hole of fusible plug is only 1/2″. Fusible plug is made of brass or bronze and contains a tapered hole. The hole is filled with tin which has a melting point of 230 deg.C. According to code, the fusible alloy should melt at a temperature of not more than 70 deg.C higher than the saturated steam temperature corresponding to the ASWP. For example, for a steam boiler of 10 bar, the saturated steam temperature is 180 deg.C; therefore the fusible alloy should melt at 250 deg.C. The use of fusible plug is limited to solid fuel and steam boiler having a pressure of 17 bar, which corresponds to tin’s melting temperature. Higher pressure would require low water alarm. That is why in a modern boiler, fusible plug sometimes cannot be found as it is replaced with low water alarm which serves exactly the same function.


Diatoms: Interesting Facts

Diatoms are tiny single-celled organisms that make up diatomaceous earth. They were first discovered in 1702 by Anton van Leeuwenhoek and for hundreds of years these microscopic creatures have been studied and analyzed. Richard B. Hoover contributed to this research by travelling the world, studying diatoms and collecting new species. In a June 1979 Edition of National Geographic, he published his exciting findings on these extraordinary organisms.

Below are some of the most exciting and intriguing findings regarding diatoms:

  • While studying a diatom collection in Belgium, that had been dried on paper in 1834, Richard B. Hoover was shocked to find that after adding water to a slide, the diatoms were revived and began to swim around… after nearly 150 years!
  • More than twenty-five thousand species of diatoms have been discovered, none of which have the same shell.
  • Diatoms exist in large numbers in most bodies of water throughout the world. In fact, just one liter of seawater can contain as many as ten million diatoms!
  • The greatest numbers of diatoms exist in cold oceans.
  • Diatoms can thrive wherever there is light, water, carbon dioxide, and nutrients. In some cases diatoms can even live out of the water – in moist conditions, they are able to live in topsoil, or attached to moss, tree trunks and even brick walls.
  • Diatoms are very resilient and can endure lengthy droughts.
  • Diatoms vary greatly in size, with the largest measuring only one millimeter across.
  • A species of diatom found on Cape Cod, known as Hantzschia virgata, bury themselves in the sand when the tide is in. Just after the tide goes out, the diatoms glide to the surface in order to sunbathe. Their timing is impeccable, as they know precisely when to bury themselves back in to the sand, retreating just moments before the tide returns. In fact, it was discovered that even after keeping these diatoms for weeks in a laboratory their timing remained constant. They continued to dig in and out of the sand with such amazing accuracy that their actions could be used to predict the tide!
  • Diatoms are impressive shell builders. They transform dissolved silicon into a silica almost identical to the gemstone opal.
  • Diatoms contribute enormous amounts of oxygen to our atmosphere.
  • Huge numbers of diatoms die and sink to the bottom of river, lake and ocean beds. In some areas, sea floors can be covered in a layer as deep as 984 feet (300 meters)! Over many years these layers of dead diatoms fossilize and become rich deposits of diatomaceous earth, or diatomite.


The Facts of Animal Testing

Alternatives to Animal Testing

As per Animal Welfare Act, the research scientists involved in animal testing are required to consider the alternative to testing on animals before beginning a research project. They must search the available literature for any alternatives, and submit their findings and search history to their concerned department.


Many people argue that as animals are less intellectually advanced (which is false statement to begin with anyway), and hence can be used to find cures for HIV, cancer or other life-threatening diseases. However, it is inhumane to take the animals out of their natural habitat, and use them for any kind of research. In US alone, more than 70m animals are blinded, maimed, hurt, killed, scalded, genetically manipulated or force-fed chemicals in the name of household products, science, educational institutes and government agencies. The animal testing is not required by the law, but is done by the companies to protect themselves from consumer lawsuits.


Testing on animals costs billions of dollars annually. To measure the severe burn on live tissue, and animal is burned alive till the flesh is charred and can be easily removed in the large pieces, while the animal is still alive. Animal’s eyelids are sewn shut, and the protein levels are measured to demonstrate that there is no difference in the levels of protein in the eyes of sight deprived. Studies on head trauma include strapping down the head of the animal, and giving high impact blows to it, resulting in severe brain damage.


Animals and humans are different, and many drugs that have been based on the animal testing had to be taken off the market due to the side-effects, that were not shown during animal studies, but proved fatal for human. There are many drugs that have passed the animal testing, but end up harming or killing the humans. Rats do not have gall bladder, dogs have different circulation system as they walk on all fours, and cats do not have enzymes that can metabolize ibuprofen.


More than half of the animal tests conducted by the cosmetic companies, and most of these studies are flawed, resulting in incorrect scientific investigations that waste money, resources and time.  More than 25 billion animals are unnecessarily killed in the labs each year. In one study, the baby monkeys were taken away from mothers, and were abused. The conclusions were drawn that neglect and abuse leads to social maladjustment and psychological damage. Such animal testing does not justify the suffering of millions of animals, and wasting billions of dollars. It is a cruel act of violence forced upon those that cannot speak up or protect themselves from the slavery that some humans seem to believe is still okay in our modern world.


There is however a possibility of using the more reliable and less expensive alternatives to animal testing. For Draize eye test, sophisticated computer models or corneas from eye banks can be used instead of using the live rabbits. Other more suitable tests include tissue culture system, chemical assay tests, human skin patches, organ and cell cultures, cloned human skin cells and computer and mathematical models.


Researchers argue that when the human life is in danger, it is better to experiment on the guinea pigs than to let people suffer or die. However, it must be kept in mind that animal testing is unjust and unethical, and there must be law enforcement to use the alternative methods.  


The Importance of Ambulance Services in Society

Certain situations in life require immediate medical care and a fraction of a second delay can drastically change somebody’s life. The ambulance service and paramedics are very important in society as they save hundreds of lives daily by responding to emergency calls. They operate from ambulance stations located in various areas with control centres that respond to emergency calls and dispatch them when needed. Whether the patient is in rural retreats, busy seaside resorts or large urban conurbations, they reach the emergency scene within minutes of the call.

The emergency ambulance service crew includes a technician and a paramedic. Once the paramedics arrive at the emergency scene they evaluate the situation and the condition of the casualty and decide whether to take them to the hospital or just treat them there. One of the important roles of the ambulance crew is to stabilize and treat patients quickly to prevent any mishap before the patient reaches the hospital.

They provide immediate and effective life-saving care in a safe and clinical working environment with maximum mobility. They are well trained in first aid skills to be able to deal with profuse bleeding, crush and fall injuries, cardiac arrests, road accidents, and much more.

During earlier times they were used to transport patients after the doctor or fire department rescue squad applied simple first aid. Mostly the patient would ride alone however, in some cases the doctor rode along in the ambulance. Today, ambulances come in a wide variety of shapes and sizes equipped with a huge range of essential pre-hospital emergency machines including heart defibrillators, intravenous drips, splints, oxygen, drugs and much more. All ambulances have radios installed in them. Many times ambulances also transport non-emergency patients that might be transferring to another hospital or treatment centre.

In some cases patients may be transported in an air ambulance which is basically an aircraft specially designed for providing emergency medical assistance in critical medical situations. An air ambulance is used when the patient has to be transported over a long distance or terrain or if the patient has to be quickly transported to a treatment centre. Air ambulances are equipped with basic equipment like ECG monitors, ventilators, medication and stretchers.

For more information regarding ambulance services in the UK refer to SearchMe4 online business directory.


How Mobile App Technology Is Transforming The Healthcare Industry

Mobile technology has its impact in the Healthcare, Medical, and Pharmaceutical industry. Mobile apps are helpful to the doctors, fitness experts, patients & hospital management staff. Doctors prescribe the patients through apps. Patients can get on-time reminders for medicine & regular health checkups. Mobile health technology has formulated the new ways that doctors can assist patients, health conscious people can remain healthy by using fitness apps. Hospital management staff can easily maintain the stock of medicines, injections & other activity by using Mobile Apps.

Medical professionals other than doctors such as medical practitioners, Hospital Management staff & students also make use of apps for the ease of all sorts of operations & routine tasks.

A survey conducted in the US reveals 62% US smartphone owners have used their phone to get information about a health condition in the year of 2015. Therefore, it is proved that mobile apps belong to Healthcare industry get a good user response.

Let’s Understand How Mobile Apps are Transforming the Healthcare Industry-

Mobile Apps for Doctors-

The medicinal services experts, specialists, Physicians and Medical understudies additionally need to experience some clinical data. For the most part, an application of a therapeutic word reference is helpful for the rehearsing specialists and understudies. For any sort of inquiry in medicinal terms, they can rapidly get the best arrangement.

Medical Apps for Doctors have normal components, for example, Medical news, Drug data and devices, Disease and Condition Information, Medical Calculators, Drug Formulary Information, Continuing Medical Education Courses, Offline Assess, and so forth.

By introducing an application, Doctors can know about the Medical gatherings plans, critical diary articles, meeting news, and so forth. Specialists can refresh themselves about the medications and dose, recipes, scales, etc.

Healthcare Mobile Apps for Patients

Owing to unhealthy food, polluted weather, tight professional schedule & disturbed routine life cycle each individual is suffering from small or big health issues.

Due to unhealthy food consumption, polluted weather, tight professional schedule & disturbed routine life cycle each individual is suffering from small or big health issues. It is better that they know about various wellbeing conditions, maladies, medals and some home cures. Best healthcare mobile applications have a decent accumulation of information including different restorative circumstances, suggestions to take prescriptions, and so on.

In some cases, the patients with an urgent need to call for the Ambulance. The applications can help you immediately when you are in critical condition. When you press the help button in an urgency numbers, get a notice about the urgency made alongside the location.

Indeed, even a Doctor can oversee wellbeing records, arrangements, Patient’s well-being history, the past and current wellbeing condition and so on. The different applications are accessible for the comfort of Doctors. With the assistance of versatile applications for patients, it’s simple for the Doctors to track a record of all patients seek the treatment. Admin department can likewise leave restorative arrangement suggestions to the patients through email, SMS, and direct application notifications.

Some huge clinics likewise oversee itemized information of all patients. A patient’s therapeutic record journal can likewise be overseen through Mobile applications.

Mobile Apps for Pharmaceutical Companies

The pharmaceutical organizations fabricate different medications and a considerable lot of them can offer their meds through the mCommerce application. As an eCommerce business has far to go, Pharmaceutical organizations, likewise have jumped into it.

They encourage you to gather the endorsed drugs from your doorstep with discounted rates. The clients can transfer a photo of the Doctor’s depiction or select diagnosis tests.

At the point when a request for the medicine is dropped, an accomplice retailer contacts the client and convey the correct medications with sensible rates. Best Pharmaceutical applications encourage the clients for well-being and therapeutic charging too.

Hospital Management with the Mobile Apps

Huge and popular international healing centers have numerous wards and treat various patients all the while. They keep an additional a staff of many individuals, including specialists, medical caretakers, ward cleaners, supporting staff, Admin, Security, and so forth. Indeed, even the master specialists from alternate healing centers likewise visit the patients conceded. Consequently, healing centers have a major information to deal with consistently. The superlative application advancement organizations can easily create the full, highlighted applications for the doctor’s facility administration.

Doctor’s facilities put a supply of different medications and solutions, infusions, operational instruments, stretchers and other gear, machines, and so forth. Stock upkeep of numerous drugs is an intense errand. The staff can utilize a particular versatile application for the same. Versatile applications show a rundown of drugs with accessible stock. Administration staff gets the warning for the pharmaceuticals with low stock and out of the stock.

Medicinal mobile applications for Doctors and patients are truly useful from various perspectives. Any medicinal expert just requires the sharp personalities for versatile application development who can comprehend their necessities and fabricate a perfect application.

Mobile Applications for Fitness freaks

In the fast paced life, individuals have turned out to be more cognizant about their wellness and wellbeing. The everyday routine includes exercise in morning and evening and managing calorie intake the applications can help with the nutrition and calorie intake.

Yoga is the best practice for physical and mental prosperity. Introduce yoga application and experience the recordings as you practice the discipline. Wellness versatile applications additionally specify how “Aasans” and “Pranayam” are valuable for wellbeing. The full-included body wellness applications can direct you precisely as the specialists.


Ayurvedic Herbal Treatment of Myelodysplastic Syndrome (MDS)

Myelodysplastic Syndrome (MDS) refers to a group of blood disorders resulting from a dysfunction in the bone marrow. This causes ineffective blood production resulting in symptoms such as anemia, fatigue, recurrent fever, heart disease, and bleeding from different parts of the body. A reduction in the immune response of the body can result in recurrent infections which may have a fatal outcome. In the late or severe stage of the disease, the patient may suffer from shock and serious secondary infection which may cause death. When there is no known cause of the disease, it is known as primary MDS. This condition is known as secondary when it results from known causes such as chemotherapy, radiation therapy, viral infection, exposure to chemicals, and having a genetic disposition to the disease.

Patients suffering from MDS are conservatively treated with packed cell transfusions which temporarily alleviate the situation; however, this can result in a buildup of excess iron in the body and result in long-term complications over time. The administration of medicines like ATG can result in improvement in about 30-60 percent cases; however the response is unpredictable and wanes over time, in addition to the treatment being prohibitively costly. In this scenario, treatment with Ayurvedic herbal medicines can be quite safe and effective in the long run. It is important to initiate treatment at the earliest in order to get maximum therapeutic benefit from treatment and a long-term remission or cure.

MDS is different from aplastic anemia in that, in addition to a lack of red blood cells and white blood cells, there are morphological abnormalities in the cells. The greater the percentage of abnormalities in the cells, the poorer is the overall long-term prognosis in affected individuals. Ayurvedic herbal treatment is focused on treating the bone marrow so as to help generate healthy white and red cells. Treatment consists of herbal and herbomineral medicines which act on the bone marrow and form the mainstay of treatment; these need to be given in high doses and for prolonged periods. Herbal medicines can be safely given for prolonged periods without any major adverse effects and are also quite economical in the long run. Medicines can be given orally in the form of tablets, and are overall quite easy to administer.

Panchkarma treatment, which forms the mainstay of treatment for serious medical conditions, is quite effective in the management of MDS as a supplementary treatment modality. Use of Panchkarma procedures helps in promoting a faster response, reduced treatment time, as well as lesser doses of required medicines. A special Panchkarma procedure known as basti (medical enema) is used very successfully in the management of various disorders. A specialized form of basti known as Tikta Ksheer Basti is utilised in MDS treatment. This consists of a series of courses of administration of milk treated with herbs. This is prepared by boiling milk with different bitter herbs which include mainly Guduchi (Tinospora cordifolia). About 100 ml of this medicated milk is administered as enema. This procedure is quite simple and can be safely given to patients of old age too without any risk of side-effects or complications.

Depending upon the severity of the condition, treatment for MDS needs to be given for periods ranging from 6 to 9 months. Complications like acute myeloid leukaemia (AML) are quite well-known in patients suffering from MDS. Such complications too can be treated successfully with Ayurvedic herbal medication and Panchkarma treatment. It is important to aggressively treat this disease so as to obtain an early remission and prevent a relapse. After this, treatment can be gradually tapered over several months. Additionally, it is also important to monitor the patient for the next few years so as to detect a relapse of the condition. Relapses can be treated with short booster doses of treatment ranging from two to three months or more.

Serious medical conditions like MDS can be successfully and efficiently managed with the help of Ayurvedic herbal treatment and Panchkarma procedures. Ayurveda thus has a significant role to play in the management of MDS.


Discrete Analyzers in the Environmental Laboratory


Think of your old manual Spectronic 20, or your direct reading spectrophotometer that you use in your lab. You line up your samples in a row. In front of them, you place some small sample cups or maybe even a series of cuvettes, and you pipette a known amount of sample into each cup. You then add a reagent and somehow mix the reagent and sample. You do this for each sample. You may have more reagents to add so you repeat the whole process until all reagents are added. Then you start a timer. When the timer beeps you know you have a certain “time window” to read the absorbance (or concentration) of your samples. You read by manually transferring the color-developed sample to a spectrometer cuvette, by using a peristaltic pump to transfer the sample to a flow cell already in the spectrometer, or by inserting the tube or cuvette that you used to develop the sample color in. Then, you press a button to send the reading to a printer, a computer program, or you manually record the reading onto a laboratory worksheet.

Did you shake and mix every sample exactly the same way every time? Will you mix them the same way every day? Will every analyst run them exactly the same way you have?

Is there color or turbidity in the samples? Should you zero your instrument with each sample, or only with reagent water blanks?

Is the exact time you read the final absorbance critical?

The process described is what you are automating by using a discrete analyzer. Instead of lining up samples, you are pouring aliquots into sample cups that are placed on an auto sampler tray. Instead of transferring a known amount of sample to a cuvette, the discrete analyzer does. Instead of adding reagents and mixing, the discrete analyzer does. Instead of starting a timer, the discrete analyzer does. Instead of reading the absorbance, recording the reading, and calculating a result the discrete analyzer does.

The analyzer has automated almost all the simple colorimetric methods for you. Sample volume is measured and dispensed exactly the same way, every time. Reagents are added and mixed exactly the same way every time. The timer is set and absorbance is measured exactly the same way every time. Results are calculated exactly the same way every time.

The discrete analyzer pipettes, dilutes, adds reagents, mixes, calibrates, measures, calculates, and reports all for you. You select a method by keyboard. There is no hardware to manually change, no cartridge to rinse out, no baselines to monitor, no wavelength filters to change. Sample and reagent volumes are determined by a selection in a computer program, not by the internal diameter of a peristaltic pump tube.

The discrete analyzer has done a lot for you but it cannot control nor do everything. It cannot accurately prepare the stock calibration standard for you, even though it can accurately dilute it. It cannot guarantee the standards and samples were placed on the auto sampler tray in the right order. It cannot prepare the reagents for you or guarantee they were placed in the right order; however, it can monitor their purity and remind you where they are supposed to go. It cannot make sure you’ve entered the proper sample ID for each sample position, however, it can guarantee that the result obtained for that sample position is traceable to the ID you entered. It cannot know the sample lot ID for each standard or reagent, but if you enter those ID’s into the software, it can guarantee traceability of those reagents with your sample sets.

The software and built in electronics constantly monitor and adjust lamp voltage so that absorbance readings do not drift. Drift is common in flow analyzers because the peristaltic pump tubing delivers reagents by proportion. The discrete analyzer delivers the exact amount of sample and reagent every time. These volumes do not change. The discrete analyzer has a fixed path length if the discrete analyzer does not transfer color-developed sample to another cuvette, or flow cell, for measurement. In addition, if, the discrete analyzer reads through the walls of the cuvette the calibration curve is usually more stable and or reproducible than your reagents and standards. 

Change your thoughts on calibration

Beer’s law states that the absorbance is equal to the absorbtivity times the path length times the concentration.  It seems, however, sometimes we do not believe that Beer’s law is a law. I say this because according to this law, the absorbtivity is a constant. When the path length is fixed (always the same), the path length is a constant as well making the only variable the concentration. Therefore, you prepare standards of a known concentration, measure the absorbance and determine the absorbtivity. Assuming you can prepare reagents exactly the same way every time, measure the same volume every time, and incubate your samples the same amount of time every time, there should be no reason to assume that the absorbtivity would change. If the absorbtivity does not change, then there is no reason to calibrate every day. Moreover, if the absorbtivity is not changing, you could actually be introducing error every time you calibrate because you may not be taking into account random errors that occur between analysts or even with yourself as you inadvertently vary your technique on a day-to-day basis.

As mentioned previously, daily calibration is required for continuous flow methods because flow methods proportion the reagents and sample using a peristaltic pump. Those pump tubes are changing with time changing the relative proportion of sample and reagents. Flow analyzers are still incredibly accurate, it is just you need to calibrate each time.

Calibrating consumes time. Especially accurate ones where you took great care to ensure your standards and reagents are fresh.

A manual spectrometer does not necessarily require a calibration each time. Many methods written for manual spectrometers merely say, “analyze a check standard with each sample set”. In fact, the stability of the calibration curve is the underlying concept behind direct reading spectrophotometers and filter wheel methods. For many colorimetric tests, the stability of the curve far exceeds the stability of the standards or the reagents. Some examples are nitrite and phosphate.

A discrete analyzer should not require daily calibrations and should allow us to extrapolate more the ion chromatography, gas chromatography, and manual direct reading spectrometer concept of the Continuing Calibration Verification, or CCV. As mentioned, the reason the discrete analyzer curves are stable is that the robot exactly reproduces everything every time. You cannot do this because you are not a robot, the discrete analyzer, however, is.

A manual method uses more reagent and sample volume because we, as humans, cannot work easily with small volumes. A flow system uses more reagent than a discrete analyzer because a flow instrument is continuously pumping reagent through the system.

Discrete analyzers that measure the sample absorbance within the same container that the reaction occurred generate less waste than instruments that wash the vessel, or use a flow cell. In fact, adequately rinsing a flow cell requires significant rinsing between samples making the waste volume generated essentially equivalent to that of a micro-flow Segmented Flow Analyzer, or Low Flow Flow Injection Analyzer.

The discrete analyzer uses significantly less reagent, and generates significantly less waste than manual methods. This chart illustrates an unscaled down manual method using the exact volumes described in Standard Methods. The waste generated for the manual method does not take into account washing of glassware. As mentioned earlier, an analyzer that washes cuvettes or rinses a flow cell will generate more waste than indicated here.

Eliminate the possibility of contamination, or false positives

The discrete analyzer measuring the absorbance of a color reacted sample contained in individual cuvettes. Unlike flow analysis, there is no possibility of interaction between samples and unlike flow analysis; the user can visually observe the reaction product during and after analysis.

Using a discrete analyzer, the analyst can observe the reaction during color development and after the test is complete. The analyst can remove the reaction segments and verify that dispensed volumes are repeatable, that there are no bubbles or turbidity, and that the color looks correct. A flow analyzer does not give the analyst the ability to visually examine and qualitatively guarantee the accuracy of his or her results.

A discrete analyzer dispenses, reacts, incubates, and measures all within the reaction cuvette without transferring to a flow cell. Analyzers that transfer to a flow cell are not “true” discrete analyzers, but instead, are hybrids between flow and discrete. The hybridization is done to achieve lower detection limits; however, the advantage of the individually contained reaction and absence of carryover is lost. In addition, since these analyzers require as much rinse as a flow analyzer to remove preceding samples, waste generation is as high as flow. Given this, and the increased possibility of environmental contamination or analyte loss that occurs from open-air heated reactions, you may as well have a flow analyzer.

Chemical reactions occur in individually contained segments

All discrete analyzers have reaction segments. Some analyzers do chemical reactions in a cuvette segment and then transfer the reacted sample to a flow cell. This type of analyzer is a hybrid of discrete and flow, and not a true discrete analyzer. A true discrete analyzer reacts and measures the sample within the optical cuvette. Some analyzers wash the optical cuvette between tests. Washing between tests enables more samples to be analyzed per cuvette; however, the washing cannot guarantee that there is no residual contamination that remaining after the washing process. Other discrete analyzers utilize disposable optical quality cuvettes.

Washing between tests enables more samples to be analyzed per cuvette; however, the washing cannot guarantee that there is no residual contamination not completely removed by the washing process. This residual contamination can come from preceding samples, or more likely, from the reagents used in processing the preceding samples. The built in computerized checking of optical quality cannot verify absence of chemical contamination.

Analyzers that use a flow cell still react samples in some sort of cuvette. It is the number of reaction vessels on the discrete analyzer that limit the number of tests that the discrete can run in a single walk away operation. If the discrete analyzer has 100 sample positions and 200 reaction cuvettes, then the analyzer can run 100 samples for 2 tests each. The discrete analyzer with the flow cell must rinse the flow cell between each sample, and rinse vigorously between each test. Consider that a two-channel flow analyzer can analyze 100 samples for two tests each in less than half the time as a discrete analyzer with a flow cell. Also, consider that the flow analyzer generates no more waste than the discrete analyzer with a flow cell. If the required testing is a lot of samples for one or two tests it makes more sense to use a flow analyzer.

Reagents can interfere as cross contamination between samples. Using disposable individual reaction cuvettes completely eliminates the possibility of contamination. For instance, the cadmium reduction nitrate test contains significant amounts of ammonia in the buffer reagent and phosphate in the color reagent. Using individual disposable cuvettes ensures that there is no contamination. Washing cuvettes, or using a flow cell, means you can never be sure.

Using disposable optical cuvettes is the only way you can guarantee no carryover between tests or samples. The concept is similar to use of disposable petri dishes, disposable pipette tips, and disposable hypodermic needles. The discrete analyzer easily and rapidly analyzes multiple tests on single sample solutions. Only disposable individually contained reactions ensure that there is no interaction between samples or tests.

Let the robot do your pipetting.

When you manually pipette samples you, hopefully, use a different pipette per sample. If not, you will at least rinse it in between samples, and possibly with sample prior to transferring your sample aliquot to the sample container. This is to avoid carryover between samples. A flow analyzer uses an auto sampler. The sampling probe immerses in the wash station rinsing the outside of the probe, and pulls wash solution from the station and into the analytical cartridge.

A discrete analyzer also uses a probe; however, it operates differently than flow analyzers. A discrete analyzer’s level detect mechanism ensures that the probe immerses into the sample or reagents no further than necessary to withdraw the required sample aliquot. The probe then washes itself on the outside at the wash station and pushes the sample or reagent out into the sample cuvette. Between dispenses, the probe pushes excess wash water out ensuring no carryover. In other words, unlike a flow system that only pulls sample in one direction, the sampling probe on a discrete analyzer is bidirectional pulling reagent and sample into its internal tubing only far enough to withdraw the correct volume and then dispensing it by pushing it out the other way.

The machine can think.

When doing a manual test you know if you ran out of reagent or sample. A flow analyzer does not know. A flow analyzer could end up aspirating from empty sample cups or empty reagent bottles all night long and think it is still running samples. A discrete analyzer with level detection prevents this. The level detect mechanism is a capacitance detector that senses the difference between liquid and air. The discrete software calculates the volume of reagents and samples based on the height of liquid. The software continuously monitors sample and reagent volumes and will not continue the test when it detects that reagents or samples have “run out”.

The sampling depth on a flow analyzer is usually adjustable by the user and is usually towards the bottom of the sample vial. On a discrete analyzer, the depth the probe immerses in a sample solution is a result of programming or instrument design. The depth sampled on the OI Discrete analyzer is determined by the level detect mechanism and the sample aliquot required for the test. For instance, if 200 micro liters is required the probe will immerse just below 200 micro liters as determined by the volume of the cup and the liquid level detected and withdraw a software-defined amount above 200 micro liters. In other words, the discrete analyzer samples from the top 300 micro liters of sample solution. The probe only immerses as far as it has to. This minimizes potential carryover contamination, and speeds the process. In this way dispensing and rinsing is fast and there is no sample or reagent carried to another on the sides of the probe. 

When sampling from the top of the sample cup there is a risk of loss of a volatile analyte from the top of the solution or the risk of the adsorption of an analyte from the laboratory air into the top of the solution. For instance, trace cyanide in near neutral solution can be slowly lost from the top layer of sample solution into the lab air. This is especially evident with lower concentrations such as 10 ppb.

Gain of the analyte is possible as well. Ammonia is a common laboratory contaminant. Ammonia readily adsorbs into acidified solutions. It is possible for ammonia to be “pulled” from laboratory air into the sample solution. A flow analyzer would not as readily detect this loss or gain because it samples from the bottom of the sample cup.

There are some drawbacks

A discrete analyzer reacts sample in a heated cup that is open to allow the probe to dispense samples and reagents. The heat increases reaction rates and is especially important for chemistries such as ammonia that are slow to develop color. In manual testing the reagents are added in open containers, however, the container shape can vary and the container can be capped during mixing, heating, and color reaction. When flow analyzers were first introduced one of the key advantages that gained its acceptance over manual methods was that reactions occurred enclosed within the tubing limiting its exposure to laboratory air. In this aspect, discrete analyzers are kind of a step backwards.

There are significant advantages.

Similar to holding a color developing reaction in its own container till it reaches a color maximum, discrete analyzers can also hold intermediate reactions for long periods of time without risk of carryover, dilution into a carrier reagents, or excessive dispersion. This can be especially useful in enzyme or reduction reactions where reaction rates are slow. A flow analyzer would require long delay coils resulting in very complex SFA chemistry manifolds. Often elevated temperature is used to speed reactions, but in some chemistry, there are limits to the maximum temperatures possible. Since discrete analyzer reactions are occurring in individually contained cuvettes, the time delay between reagent additions on discrete analyzers is limited only by software. This is a significant advantage over flow chemistry.

In manual methods, obviously, the operator prepares all the calibration standards from a stock solution, dilutes any QC samples from a stock solution, dilutes samples known to be over calibration prior to color development, and dilutes samples that were over calibration once he or she notices that they are. Unless you have an added auto-dilutor attached to your flow analyzer, you will still be diluting standards and over calibration samples. Auto-dilution is an integral function of a discrete analyzer. The dilutions can be preset during sample table entry if you know that the samples need to be diluted. Methods can be programmed such that they dilute every sample and standard all the time, or the instrument can be programmed so that over calibration, samples are diluted and re analyzed.

An analyst changes a manual or flow method from one to the next by memory, or by referring to the SOP. How well this particular analyst performs the procedure is dependent upon his mood, the time of day, his experience with the method, the availability of equipment, and many other unquantifiable variables. It is possible to obtain good results and bad results by the same manually performed method. A flow analyzer analyzes everything the same every time assuming it is set up the same every time. This assumption is valid with experienced flow analysis technicians; however, if the technician does not understand flow or if there are multiple users results will vary. Extensive training and documentation is necessary to guarantee that results conform to good automated lab practices.

The discrete analyzer method is selected by mouse click when scheduling analyses on the sample tray. The method conditions do not change. In fact, assuming you have accurately calibrated your method the calibration is stored within the method. This means that an untrained analyst that only knows what buttons to press is able to obtain identical results to even the most experienced analyst.

Most analytes performed in an environmental compliance laboratory cannot be bench spiked. If the analyte requires a preliminary distillation, digestion, or extraction the spiking is done prior to the preliminary sample process. I realize that many labs do not distill ammonia or Fluoride and I would argue that if you are reporting compliance testing for the clean water act you would better seriously consider changing your SOP. Other parameters that can’t be spiked are those that are too high to spike within the matrix without preliminary dilution, such as Ca, Mg, Cl, SO4, and analytes like alkalinity that just are not spiked.

This shortens the list of potential analytes for the automatic spiking function to nitrite, phosphate, Sulfide, Chromium VI, and some others. On these, I defer back to the previous slide and ask if the potential error is worth the risk for so few tests.


Benefits of discrete analyzers include decreased reagent consumption, decreased waste generated, and ease of use among other things. The most significant advantage of the discrete analyzer, however, is that it can eliminate the traditional concept of routine analysis and allow you to run samples as you receive them instead of storing them until there is enough sitting around to make a flow or IC analysis worthwhile. If you take advantage of the calibration stability of the discrete analyzer, and accurately prepare a calibration that can then be used by almost any analyst in subsequent uses an added benefit is that the results are the same regardless of who uses the machine.

Think of those short holding time samples. The phosphate, the nitrites, the chromium VI, and residual chlorine. These analytes cause the environmental lab to stop everything just to get the analysis done on time. Think of the other analytes that come in periodically, but maybe not frequently. Possibly silica, ferrous iron and sulfide. How do you guarantee these tests followed the SOP? Instead of thinking of the discrete analyzer as something to replace a flow instrument, think of it as something to supplement a flow instrument. If you have hundreds of samples for one or two tests routinely and for the same analyte you are not going to save money by switching these tests to a discrete analyzer. Where you will save money and great effort is removing unnecessary strain from the flow analyzer and your analysts by performing the non – routine or “rush” tests on a discrete analyzer. It is possible for the sample login person to analyze samples as received for almost every colorimetric test that does not require a digestion. In other words, as soon as the sample is logged in it could be immediately run for nitrite, phosphate, chromium VI, nitrate, ammonia, chloride, and sulfate. In this example, instead of putting samples in a refrigerator to be gathered for analysis at a later time, they end up being run by ice chest and by client as soon as they are received.

If everything is to run on the discrete analyzer, then collect your samples in a vial that fits on the discrete analyzer. You no longer need to transfer liquid from container A to auto sampler vial B, the sample bottle can be the auto sampler vial. Not only does this save time, but it saves shipping as well. Instead of large ice chests, you use tiny mailers.

To summarize, the true advantage of a discrete analyzer is that its built in features allow any analyst to get the same results every time. Discrete analyzers are very simple to use requiring minimal software training. Once set up for your laboratory, properly applied methods allow you to modify your daily routines and analyze samples as soon as they come in. Whether you are an environmental lab, research, process control, or municipality discrete analyzers can be used effectively in your operation. Currently, the full power of discrete analyzers is limited by tradition and by regulation. Once we start to develop methods for discrete analyzers instead of using discrete analyzers to run methods developed for flow we will be able to see greater throughput, less variability, and lower MDL.