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Tuesday, September 27, 2011

#27 - Analysis of Oxygen by Paramagnetic Detection

Introduction

Nova makes the Model 322BT oxygen analyzer. This instrument is designed for continuous analysis of up to 100% oxygen (O2) in process gas streams that do not contain any condensable water vapor or oil vapors.

The analyzer utilizes a paramagnetic type sensor, which responds quickly to process O2 changes.

Operation

The Nova Model 322-BT Oxygen Analyzer utilizes a high stability, magneto dynamic paramagnetic cell for the detection of oxygen in the sample gas.

Oxygen has the unique property of being attracted to a magnetic field, as discovered by Michael Faraday. Most other gases are diamagnetic (repelled by a magnetic field).

A strong magnetic field passing through the magneto-dynamic cell attracts oxygen which enhances the magnetic field. This in turn increases the force on a diamagnetic body suspended in the field.

The diamagnetic body consists of two glass spheres filled with nitrogen and suspended on opposite sides of a taut platinum ribbon between the poles of a strong permanent magnet assembly. A small mirror is also attached to the platinum ribbon which will detect any angular motion.


As the oxygen content in the sample increases, the increased magnetic field increases its repulsion force against the spheres. An infrared light beam focused on the mirror reflects onto a pair of matched infrared detectors mounted side by side. Any angular movement of the platinum ribbon by the repulsion force against the spheres causes the light to reflect more on one IR detector than the other, causing an increased current output from the amplifier. The current is fed to a feedback coil consisting of a single turn of fine platinum wire secured around the spheres. The magnetic field created by this current opposes the force due to the oxygen present in the sample gas and consequently the spheres remain in their original position.

The current required to hold the spheres in the neutral position is directly proportional to the amount of oxygen in the sample gas. By measuring this current, we have a direct measurement of oxygen. An amplifier built right into the cell, converts this current to a 0-1 VDC output representing 0-100% O2. This 0-1V output is then sent to the main amplifier board which then has calibration adjustments, output circuits, and connections to the front panel display meter.

Check out the Model 322 brochure…

While the paramagnetic detector is a quite accurate method of oxygen analysis, we have found that it is somewhat sensitive to external vibration. For example, the constant handling and jostling implied in a portable analyzer can affect the stability of the readings. For most applications, we manufacture this analyzer in a bench top style cabinet. It is basically a sheet metal box with a carry handle on top and a readout on the end facing the user. (See above picture) This cabinet style usually finds it home on a laboratory bench or some other stable surface.

Added March 23, 2013 - We have also noticed that paramagnetic detection is very sensitive to sample pressure and flow. It is very important that we have a clear idea of what the pressure and flow characteristics are of the sample gas. This also applies to the vent flow. It is preferable that this type of detector have an unobstructed vent to the ambient atmosphere.

Alternatively, you might consider an electrochemical O2 sensor. The accuracy and range may not be as high as a paramagnetic detector, and may be a little slower in some cases. However, it is generally quite rugged and well-suited for many applications. Check out the Model 320 brochure…

We make gas analyzers for oxygen, hydrogen, carbon monoxide, carbon dioxide, methane, and many other atmospheric gases. We provide gas analysers for syngas, landfill gas, purity gas, biogas, and others.

Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com
http://www.nova-gas.com/

Wednesday, September 21, 2011

#26 - 7 Billion

No doubt you have seen articles around the newsstand and the internet that announce the recent arrival of the 7 billionth baby on this earth. (Actually, the number is 7,005,658,370 at the moment of this writing.)


It is probably somewhat misleading to say ‘7 billionth baby’ because the world’s population is a dynamic mixture of simultaneous births and deaths. But the idea still remains that we have passed a significant population mark.

A billion of anything is beyond the scope of our minds to intuitively grasp in the same way that we think about 10’s, 100’s, or 1,000’s. From an early age, our minds exploit regularities in our environment. Recurring number quantities acquire a meaningful ‘feel’ so that we can make qualitative evaluations and comparisons. But very large numbers that cannot be quickly evaluated visually or viscerally may not acquire deep meaning for most people. The earth’s population is one of those numbers.

Looking at various aspects of the world’s population growth can help us come to a more meaningful understanding of what the numbers signify.

Exponential Increase – So far, it has taken progressively less time to reach each billion mark.


Locations of Increase – ‘More developed’ areas have had reductions in fertility, while ‘less developed’ areas have maintained or increased fertility. The net result is that 82% of the world’s population lives in less developed regions as compared to 68% in 1950.


People ask where all of this is heading. The general idea is that worldwide population is supposed to level off at some point in the future and achieve some kind of equilibrium between mortality & fertility. Perhaps this is an accurate prediction, perhaps not. Perhaps Malthus will yet be vindicated.

A more relevant question might be – are the trends sustainable? As we wander into the future towards the predicted equilibrium or the predicted disaster, how much misery will be sustained by people in less developed regions? How much consumption by developed and developing regions can be sustained by the environment?

When we say ‘sustain’ in this context, we mean a couple of things. ‘Sustainability’ has become associated with the environmental concept of consuming renewable resources instead of non-renewable ones. This is a good thing; a responsible way of living and doing business. Because of their high rate of consumption, the developed and developing worlds definitely need to improve in this area.

‘Sustain’ also means to keep alive by nourishing. This is a rather fundamental thing. Can the earth keep us all alive for the foreseeable future? The answer is yes. The earth has plenty of capacity for billions of inhabitants. The issue is not one of population numbers, real estate, or resources. It is really an issue of better management and distribution that is more focused on the actual welfare of humankind. Best management practices in this case would undeniably be influenced by economics, but preferably without the greed component that is all too often present.

A more meaningful distinction between 'needs' & 'wants' is probably in order. The high rate of needless consumption in the developed world is already a serious environmental concern. If and when the non-developed and developing worlds adopt the same fascination with material trinkets, the situation will probably become a catastrophe.

Another component is education. Among the highlights of the 2008 World Population Data Sheet produced by the Population Reference Bureau, it was noted that in most regions, a mother’s education is key to children’s nutritional status and ultimately to their health and development.

There are many other factors to consider when evaluating the earth’s potential for human sustenance. We do not claim to be experts in this field.

At Nova, we make only a tiny contribution to environmental issues. We provide the analytical equipment required for measuring atmospheric gases such as oxygen, carbon monoxide, carbon dioxide, methane, hydrogen, and others. We are happy to assist with syngas, gasification, and other renewable and recovered energy applications because these make novel use of non-traditional energy feedstocks. Ideas like this will hopefully contribute in a small way somehow to better care of the world’s growing population.

Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com

Population graphic & information taken from - http://www.prb.org/

Graphs compiled based on information from the International Society for the Comparative Study of Civilizations (ISCSC) - http://worldhistorysite.com/population.html

World Population Data Sheet for 2011 - http://www.prb.org/Publications/Datasheets/2011/world-population-data-sheet.aspx

World Population Data Sheet for 2008 - http://www.prb.org/pdf08/08WPDS_Eng.pdf

http://singularityhub.com/2011/09/06/hold-world-population-to-reach-7-billion-this-month/

Tuesday, September 13, 2011

#25 - "Disconfirmation Bias" and other decision-making aids

When joking recently about our decision-making process, we came across the term “disconfirmation bias”.

It’s defined as “The tendency to accept supportive evidence of a belief uncritically, but to actively refute or discount evidence that challenges that belief.”

There are many areas of the human sphere that are susceptible to disconfirmation bias.

I have to work hard to keep this decision-impairing tendency in check. For example, my wife and I were shopping for a new home recently. I was quick to point out deficiencies in building sites that I didn’t like while subsequently minimizing those same deficiencies in the sites that I favored. We do this all the time when evaluating the merits / flaws of people we like vs. those we may be prejudiced against.

To avoid wandering too far into controversial territory, perhaps we should just stick to the workplace. Have you seen evidence of disconfirmation bias in your workplace process?

The strength of beliefs is generally revealed in the context of proposed or implemented changes. When the situation is statically in our favor, our beliefs about the situation are somewhat idle. Not necessarily dormant, just not strongly enacted. Like a car engine that is on, but not yet in gear. But when a change is proposed by others, or when we are the ones proposing the change, beliefs and values are inevitably challenged.

It isn’t the challenges per se that pose the problem. It’s how we react to them that reveals our true inclination. Are we biased in our refuting and accepting of relevant evidence?

At Nova, we make analyzers for gases such as oxygen, hydrogen, methane, etc. There are numerous components that are incorporated into the design of an analyzer, whether it is a little portable monitor, or a large on-line continuous analyser. If an impaired decision-making process were to result in a misguided design, in most cases it would not be cause for life-threatening concern.

My wife recently brought some work home with her. She was doing some literature research into post-operative care of cardiac surgery patients. The focus of her work was proper protocol on sternal incision care after heart surgery. I don’t claim to understand all of the research, but it was amazing to see how much disconfirmation bias she found in situations that are much more critical to people’s lives than gas analyzers. Accepted medical practice in this situation had been sustained for decades based only on tradition rather than evidence-based research. Her findings, when presented to her cardiac staff, stimulated much discussion and proposals for protocol change.

After thinking about that situation, I didn’t feel quite so embarrassed about the occasional gaffe here at Nova. After all, a valve or a pump in a gas analyzer can be fixed. The customer can be trained to calibrate semi-regularly. While the valves in the human heart can be fixed if necessary, it’s best not to have bias in this field of practice. (This whole episode scared me into exercising more regularly.)


So be on the lookout for this now. With a cool name like “disconfirmation bias”, it will probably be the next big thing.

We’re Nova. We make gas analyzers for oxygen, carbon dioxide, methane, hydrogen, and other gases.

Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com

If you have a LinkedIn account, search for us under Companies and follow us.

Picture ownership unknown. Sources:

http://collaborationnation.wikispaces.com/First+African+American+to+do+open+Heart+Surgery
http://www.usswisconsin.org/Pictures/1950%20Pic/513%20W.%20Lehtonen%20Operating%20Room.JPG

Wednesday, September 7, 2011

#24 - A walk in Nova's neighborhood

We are frequently questioned about Nova’s physical locations.

How about a walk in our neighborhood?

We actually have two neighborhoods. One in the USA, and one in Canada. We are a manufacturing company, so our neighborhoods are not that glamorous. But our location in Canada does have some interesting history.



We are tenants in a historic industrial building erected in 1900. The complex formed one of the centers of Canada’s cotton textile industry and remains today as one of the most complete historic textile mill complexes in Canada. Originally, the mill produced cotton tarpaulins, tents, vehicle covers, and various fabric products used by the military in WWI and WWII. Later in the 1960’s the facility was re-equipped for lighter cotton manufacturing. Textile-related manufacturing eventually ceased on the site in 2001.

The complex currently houses mixed tenants with a focus on the creative arts. The TH&B Artist Collective, The Imperial Cotton Centre for the Arts, and several individual artists and photographers occupy much of the site. A few tech companies, including Nova, occupy other areas of the complex.

The site also functions as a movie set. Movies, TV shows, videos, and other productions are regularly filmed on the site. I am expecting my big break in the movies to happen any time now.

The picture below is of our area disguised as a tropical office building for a movie. Doesn’t look too convincing in these pictures, but I assume it worked well in the film. The picture below that is an alternate location which I would like to propose for our sales office.



So that’s a blog post about where the Canadian side of our family lives. In a future post, I will share some cool info about our USA location.

We’re Nova. We make gas analyzers for oxygen, carbon dioxide, methane, hydrogen, and other gases.
Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com

http://thbcollective.com/
http://www.imperialcottoncentre.com/
http://www.270sherman.ca/Site/Welcome.html

Here’s a link to a picture archive of some other cool historic industrial sites:
http://www.hfinster.de/StahlArt2/archive-Various-en.html

Thursday, September 1, 2011

#23 - Hey this is cool - Ripley's new aquarium coming to TO

Everyone loves aquariums! New one coming to Toronto Canada in 2013 at base of CN Tower. Ripley Entertainment Inc. is building it.

Read all about it at:
http://www.ripleysnewsroom.com/rac/



At Nova, we get a number of inquires for water quality analyzers. Unfortunately, water analysis is out of our area of expertise. We focus on gas atmosphere analysis only.

One water-related application that we do address frequently is chlorine-in-air analysis at swimming pools. Nova Model 541 Continuous Chlorine Monitor is designed for monitoring the atmosphere in and around chlorine storage areas at swimming pools. Waste or fresh water treatment plants sometimes also have on-site chlorine storage which may require monitoring.

Check in out in our on-line catalog…



Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com
http://www.nova-gas.com/