As mentioned in a previous post, Foxcroft assisted in providing a water meter test bench to the City of Ambato, Ecuador last September.
In January of 2012 we and representatives of the Mars Company, the test bench manufacturer, were pleased to visit and provide start up assistance for the system delivered just after Christmas.
The process started when officials with EP-EMAPA, the Municipal Drinking Water and Wastewater Company of Ambato, estimated the city was losing about $1 million dollars per year in drinking water revenue between meter tampering and inaccurate water meters.
Management decided the first step was to address the most widespread issue, questionable meter accuracy. Rather than continue past practices, he believed the city would be best served by conducting its own meter testing and upgrading to the latest technology built to meet AWWA recommendations and NIST Handbook 44 specifications.
Electro-Mechanical Systems Engineer Max Pico chose the Mars Model 5-1000, an automatic double row bench that can test up to (10) meters 5/8" through 1" in one row, and up to (5) 1-1/2" through 2" meters in the second row with 1/10 of 1% repeatable accuracy using the gravimetric method. The system included a 500 gallon stainless steel tank and a 10 gal / 100 gallon duplex stainless steel tank. The system was provided and installed by our partner Amimechanical S.A of Quito, Ecuador.
Engineer Max Pico, left, at the Mars Co. computer control panel with a plant operator.
The test bench, which is compliant with ISO 4064 specifications, will help the city recover revenue lost to inaccurate water meters. In addition to testing the performance of their existing and newly purchased water meters, the bench will also provide valuable data to help evaluate future meter purchases.
Mars Co. president Floyd Salser with the Mars Model 5-1000 test bench in Ambato Ecuador
Since these test systems often pay for themselves in less than one year, we're looking forward to updates on how the test bench is contributing to their meter management program.
I wanted to share a good idea that can help save money on chlorine gas while protecting your personnel.
Brian Gunn, of Coastal Chlorinators in Savannah, GA has a customer who prefers dual channel chlorine gas detectors in his remote well sites instead of the typical one sensor gas detector.
The customer places one sensor inside the well house to protect personnel, and the other sensor outside at the vent, so it will alarm if the chlorinator malfunctions. With the detector's alarm relay connected to a phone dialer, officials can be notified immediately instead of being surprised during an onsite visit after a month of wasting gas.
Of course, the environment is also protected from a prolonged chlorine gas leak.
If you have any other "cool tricks" please feel free to share them. When it comes to water and the environment, a good idea can benefit everyone.
Foxcroft Equipment & Service was honored to participate September 29, 2011 in an international conference "Technologies for Efficient Potable Water Service" hosted by EP-EMAPA, The Municipal Company of Potable Water and Sewage Systems of Ambato, Ecuador.
Held in the Hotel Miraflores in Ambato, the conference was attended by EMAPA of Ambato officials, water system officials, technicians, and companies from other cities, as well as Foxcroft sales manager Ray Sullivan.
Pictured L to R: Leonardo Herrera, Amimechanical, SA; Engineer Max Pico, EMAPA Chief of Electromechanical Systems; Ray Sullivan, Sales Manager Foxcroft Equipment; Engineer Rafael Maldonado, General Manager EMAPA; Galo Hinostroza, General Manager ASUBSA Aguas Subterraneas.
One objective of EMAPA for the conference was to share with other municipalities the method to improve the quantity and quality of drinking water while reducing operating costs through automated control systems. Savings allow the possibility of reinvestment in other projects to serve their customers.
Engineer Rafael Maldonado, General Manager of EMAPA, believes investment in high quality, current technology is essential to provide his customers with a reliable supply of safe drinking water in a cost effective manner.
Foxcroft offered two presentations: the disinfection of potable water, and the Mars Company automatic water meter test bench being supplied to EMAPA of Amabato.
Engineer Max Pico, Chief of Electromechanical Systems for EMAPA presented the SCADA system recently installed by Leonardo Herrera of Amimechanical, SA; Foxcroft's representative in Ecuador. The SCADA system included equipment and instrumentation supplied by Foxcroft.
Pictured L to R: Leonardo Herrera, Amimechanical, SA; Ray Sullivan, Sales Manager Foxcroft Equipment; Victor Mendez, Technical Director, EMAPAR, City of Riobamaba; Engineer Rafael Maldonado, General Manager EMAPA.
In an effort to conserve water more of our customers are asking about reducing the sample flow rate into their FX-1000P series chlorine residual analyzers.
Discussions with customers sometimes reveal that the sample flow is turned down so far that the water is draining from the sample cell in drops or a trickle.
There are two major problems this causes:
1. The gold positive electrode can be damaged. Water flowing through the sample cell cools the electrode. Without sufficient flow the electrode overheats, deforms, and stops functioning properly.
2. You will get unreliable readings with any amperometric chlorine residual analyzer if a minimum consistent flow isn't maintained.
Also bear in mind that to measure the same residual as your process it's important to send the sample to the analyzer as quickly as possible, especially when using the analyzer to control chlorine feed.
To see how the recommended flow from the (left) measuring cell drain should look please check out the video below. A blue "PA Rural Water" pen is placed next to the drain for size reference.
You may notice the overflow from the drain on the right is less than the drain from the measuring cell on the left. That's OK, maintaining the measuring cell drain flow is more important.
For those who prefer numbers, the recommended sample flow into a standard analyzer is 500 ml/min. The minimum sample flow into a standard analyzer is 250 ml/min. The minimum flow rate from the measuring cell drain is 130ml/min.
If you must minimize water usage we recommend using the FX-1000P-RM flow rotometer. With this unit you bypass the overflow weir and feed the sample into the measuring cell. By using the FX-1000P-RM's pressure and flow control, flow into the analyzer can be reduced to 2-1/2 to 3 GPH (157 to 189 ml/min).
Flow consistency is just as important as flow rate. Amperometric chlorine analyzers are flow sensitive. If you reduce the flow to your analyzer and make no other changes to your system the residual will decrease as well.
So if you decide to reduce the flow to your analyzer, don't set it below the minimum recommended flow rate and don't forget to recalibrate!
Are you really sure you want someone to change the setting in a toxic gas detector that determines whether you're notified of a hydrogen sulfide or chlorine gas leak?
At first glance field adjustable settings may seem like a great feature; flexible, modular and easy to do too. But be careful, it may be too easy.
I Can Be Dangerous; and, Stuff Happens
If I'm responsible for the safety of others, I don't want a guy like me to have the ability to change alarm levels. I'm cautious and careful, but occasionally I transpose numbers, or may skip a step in a procedure due to any number of things that are happening on a bad day. That's a dangerous combination with a gas detector.
Beside simple human error, other risks with field adjustment include deliberate tampering, and even worse, settings made by authorized personel with good intentions who don't have a full understanding of a system or instrument.
Things can go wrong so easily and in so many different ways, especially with complex systems. I marvel at how the unlikeliest, once in a life time sequence of events can somehow come together to cause a tragedy. For these reasons and more, you need to minimize the potential for error or malfunction in your gas detector.
You Need Backup
It's important to remember how dangerous these gases are and to be aware of how the body responds to them. Carbon monoxide is colorless, odorless, and tasteless. Overexposure symptoms can be mistaken for food poisoning or the flu. A victim can slip into unconsciousness and away without ever realizing what happened. Our ability to smell some gases can be diminished by prolonged or excessive exposure. Check out this informative article by James Moore on olfactory fatigue and how stress can affect our sense of smell.
Keep It Simple
Our approach to gas detection at Foxcroft incorporates the KISS principle, Keep It Simple Stupid, coined by engineer Kelly Johnson of Lockheed Martin.
Even though Foxcroft toxic gas detectors include the finest gas sensors available, we've chosen not to provide field adjustable settings or or risk transmission interference with wireless sensors. We've avoided a high level of complexity in operation, installation and calibration to minimize the potential for error.
While we offer "non-standard" operating ranges and custom alarm levels upon request for applications not related to personal safety, we don't make them field adjustable.
Remember what you're trying to do
With more features being developed through rapidly changing technology, we need to remember the purpose of toxic gas detectors: accurate, reliable gas detection and notification, all the time.
Before committing to a detector with adjustable alarm levels or any other "advanced features", determine if they're truly needed for your circumstances or the application. If so, does the detector include a means to prevent improper alarm settings or other human generated errors? In any event, develop a gas detector protocol that includes plenty of checks and balances.
To maximize your margin of safety, keep it simple to minimize the number of things that can possibly go wrong. The gases you're working with may not give you a second chance.
Congratulations go out to our customer Palm Coast Water in Palm Coast Florida for 2011 Best Tasting Water honors in the Northeast Region II for the Florida Section of the AWWA.
This crew is good, it's their fourth first place win, in addition to two second place and a third place finish in previous competitions.
The city's TOP OPS team has also won seven straight state championships in the AWWA's question & answer competition, the only team to do so.
Here are some links on the news release reported by The Daytona Beach News Journal.
Palm Coast uses the Foxcroft FX-1000P amperometric chlorine residual analyzer.
Customers who have trusted Foxcroft gas detectors for 10 to 20 years have been somewhat cautious at the prospect of changing to our new standard Easy Cal Chlorine gas sensor.
The don't "mess with success" mentality is understandable, especially with personal safety equipment. While we agree with that, we still try to improve our gas leak detectors to increase our customers' margin of safety.
The Easy Call sensor uses the identical 3-electrode chemical cell as our traditional sensors. You'll get the same high performance that you've expected and received in the past.
The difference is the 4-20mA transmitter board: the Easy Cal features push button calibration, whereas our traditional sensors use potentiometer adjustment with a jeweler's screwdriver. The result is faster, easier calibration.
The benefits of Easy Cal include:
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Assurance that calibration is done properly.
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Lower maintenance and installation cost due to faster calibration, especially welcome for two sensor or four sensor gas detectors.
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A greater probability that detectors will be calibrated since it is so simple.
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The Easy Cal in many cases seems to stabilize more quickly, which may allow you to calibrate an extra sensor or two from a calibration gas cylinder.
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The ability to restore factory settings.
In addition to Chlorine, Easy Cal sensors are available for Hydrogen Sulfide, Sulfur Dioxide, Hydrogen, Carbon Monoxide, and Nitrogen Dioxide in our fixed gas detectors.
You can monitor Ammonia, Hydrogen Cyanide, Hydrogen Chloride, Nitric Oxide, and Ozone, as well as the gases listed above, with the Ready Advanced series of sensors, which feature push button calibration and enhanced performance. We'll highlight these sensors later.
While we stock chlorine sensors with the Easy Cal transmitter boards as standard, we can still provide our traditional sensors upon request with a two week lead-time.
Welcome back to Foxcroft.com Blog, this is the second part of the blog that was posted on 5/20/11.
The cell probes are connected to the amplifier section of the electronics, where the low level amperage is boosted and ranged to a usable signal. Specifically, 0 to 5 volts DC. The 0 to 5 VDC is then input to and isolation amplifier, which provides electrical isolation and an electrical safety barrier. The 0 to 5 VDC output of the isolation amplifier is then doubled to 0 to 10 VDC, which is used in the final 3 output stages of the circuit. These are the LED display, the alarm circuit and the 4-20 milliamp DC output signal. The amplifier board is powered by a dual bi-polar regulated DC power supply, which provides two sets of +12 and -12 volts. The LED display provides an instantaneous numerical reading of the chlorine residual in parts per million.The alarm circuit provides two user adjustable alarm level settings that activate two relay outputs, which can be used to control external devices or alarm annunciators. The FX-1000p amperometeric chlorine analyzer has been design with process control applications in mind, and as such, is an excellent choice for use in process control of chlorine residuals in freshwater, wastewater, salt water and food processing.
Amplifier board calibration is done at the factory, with a default range of: 0 to 5 ppm. The unit can easily be re-ranged in the field. The analyzer can be ranged anywhere from a low of 0 to 0.5 ppm to a high of 0 to 60 ppm. On-site standardization (chlorine residual calibration) is done when the unit is commissioned, and thereafter needed or desired, using an accurate chlorine residual titrator (or test kit), and chlorinated and non-chlorinated sample of the process waters being analyzed.
If you would like more information or a quote please click on the following link:
Occasionally we encounter flow reduction or blockage in chlorine analyzers monitoring certain groundwater sources.
We examined this problem at a well station in our area that chlorinates and monitors ground water. The water drawn from the sample tap, unlike aerated "white water", was initially clear with some microbubbles of dissolved oxygen or gases.
These microbubbles decompressed and expanded into clusters of larger bubbles to restrict the orifice in the analyzer flow cell. The blockage would trigger a low chlorine alarm and require extra attention from the operators to remain in compliance.
In our research we found that bubble traps or bubble eliminators can provide mixed results in some applications; so we decided to prevent bubbles from developing within the analyzer.
Our FX-1000P Rotometer keeps the sample pressurized through the flow cell orifice until it reaches the measuring cell. Since the residual is determined almost instantly, the sample overflows to waste before bubbles have time to enlarge and cause problems.
The controlled flow also eliminates the need to recalibrate due to flow rate changes, which simplifies consistent, accurate chlorine residual measurement. It's easy to install and includes a pressure regulator with gauge.
Foxcroft Equipment & Service Company's FX-1000p is an Amperometric Chlorine Analyzer, which means that the chlorine residual reading is determined by reading the electronic amperage of the measuring cell. The amperage level is directly proportional to the level of free chlorine available in the sample stream. When reading total chlorine, the unit is actually reading converted free iodine from potassium iodine that is added to the cell for Total Chlorine readings.
The cell itself is constructed such that the sample that runs through it does so at a continuous and fixed rate. Any additional flow is allowed to overflow to waste from a drain below the overflow weir. The sample stream rums down though the lower block, where it mixes with vinegar (and Potassium iodide where Total Chlorine is being analyzed), and then flows upward through the measuring cell. Within the cell, the vinegar provides pH buffering to a value of 4.0, and aids in keeping the cell clean. If Potassium Iodide is being used to read Total Chlorine, it chemically converts any free and combined chlorine residuals in free iodine, which is then read as a total chlorine reading. The cell utilizes a mixer and 150 pvc balls to ensure even chemical mix, clean probes and consistent readings. Very pure grades of gold and copper are used in the construction of the probes to ensure accuracy. Sample flow leaves the cell from the top and runs out a secondary drain to waste.
Come back on Monday 5/23/2011 for Part 2!
Written by: Gavin McCulloch