|After several accidents involving overloaded containers or improperly packed cargo transport vessels, the International Maritime Organization (IMO) took steps to address these issues. IMO oversees the Safety of Life at Sea (SOLAS) convention, and passed the new amendment in May 2014 taking affect in July 2016 after reviewing existing regulations.
Before containers, cargo, and goods can be loaded onto vessels, the VGM (verified gross mass) is required for containers, cargo, and goods. Weighing can be done in one of two ways, called Method 1 and Method 2, on scales calibrated and certified to the national standards of the country where the weighing was executed. Method 1 requires weighing the entire loaded container, cargo, or goods. Method 2 requires separate weighing of everything placed inside the container, including cartons, crates, pallets, and materials used to pack and secure the items. Individual weights are totaled and added to the weight of the empty container to arrive at the VGM.
According to SOLAS, scales must meet certification and calibration standards issued by the country in which the scale is operated. Intelligent Weighing Technology, Inc. offers a services for certification, scales, and meets all the requirements of SOLAS. We offer a variety of industrial scales that can help shippers and carriers with SOLAS compliance.
Just look for the SOLAS Compliant logo.
Almost all of us are familiar with static electricity because we can see and feel it in the winter. On dry winter days, static electricity can build up in our bodies and cause a spark to jump from our bodies to pieces of metal or other people’s bodies. We can see, feel and hear the sound of the spark when it jumps.
In science class you may have also done some experiments with static electricity. For example, if you rub a glass rod with a silk cloth, rub a plastic comb against a man-made fiber, or if you rub a piece of amber with wool, the glass, plastic and amber will develop a static charge that can attract small bits of paper or plastic.
Static electricity is all around us, especially in the metal and plastic world of the laboratory. Mostly, we can deal with this inconvenience, but when you bring balances into the equation, it becomes tricky.
To understand what is happening when your body or a glass rod develops a static charge, you need to think about the atoms that make up everything we can see. All matter is made up of atoms, which are themselves made up of charged particles. Atoms have a nucleus consisting of neutrons and protons. They also have a surrounding “shell” that is made up electrons. Typically, matter is neutrally charged, meaning that the number of electrons and protons are the same. If an atom has more electrons than protons, it is negatively charged. If it has more protons than electrons, it is positively charged.
Just as the static electricity attracts pieces of paper and plastic, it also attracts metals to one another. This attraction means that a balance which has been calibrated, may weigh differently when say a plastic weighing boat is placed on the platter, The static in the boat will be attracted to the pan and the metal parts of the balance will be attracted to the boat and anything else around it.
A recent study of static electricity present in a plastic weigh boat gave an error of more than 4 grams on a perfectly calibrated, good quality balance. This was a 4 place (0.0001 g) balance, which represents an error of 40,000 divisions. A hopeless situation for weighing.
As many materials are affected by static, such actions as trying to pour powders into a weigh boat on a balance platter can end in disaster as the powder can often be seen to change direction in mid-air and stick to the nearest attracting surface.
There are several options for dealing with the problem of static.
“Static Gun Ionizers”
A simple solution of an Antistatic Gun which generates either a positive charge or a negative charge, depending on if you are squeezing or releasing the trigger. The charges are generated by the excitation of piezoelectric crystals, and by skillful use of the trigger, most static conditions can be neutralized. The Zerostat is cost effective, easy to use, but does have a finite life of approximately 10,000 “Squeeze cycles”. What is more, you have to actively generate negative or positive ions yourself, the unit does not “control” the electrostatic situation, you do.
“Polonium Alpha Ionizers”
This is a Polonium 210 element which emits alpha particles (positively charged atoms) which collide with molecules of air, creating a supply of oxygen and nitrogen ions sufficient to neutralize both positive and negative static charges.
They are completely safe as the alpha particles will not pass through the skin, however some people may need to be convinced of that. They are silent, clean and are easy to fit to existing equipment such as balances. They are medium priced, but again, they do decay over time and need to be replaced after a year or so.
The Intelligent Ionizer is an elegant solution to the static problem, however it is more costly than the first two technology examples.
It is an electrically operated DC Corona discharge type. Using high internal voltages, it generates ions with a high parity balance. Completely safe, it is convenient for use in laboratories of all types.
Unlike some electronic solutions, the Intelligent Ionizer does not create a large “wind” or draft, thus reducing the effect on your weighing results of high resolution balances. It is portable, safe, clean and easy to use. It can cover a large area, (up to 700 mm / 27”) away from the unit, making it ideal for laboratories. It has an extremely long life and should not need to be replace in decades, therefore the initial expense can be amortized over a much longer period.
Our featured article from February’s issue of Industrial Weigh and Measure Magazine is now available online. You can read it here
Thank you to everyone who came and saw us at Pittcon this year. Below is a gallery of our booth in case you missed us.
The Internet has enabled many customers to easily reach web sites and view competing pricing for items. This is a good thing for good old fashioned competition, which is what this country was built on!
However, in the world of weighing, sometimes it is not that simple. Just because the capacity (how much the scale or balance will weigh) and readability ( the smallest division of capacity that the balance will display) are similar, doesn’t mean that weighing results will be the same from balance to balance.
Many factors influence the weighing machine.
Plastic is cheap and efficient but will allow the build-up of static, (static electicity can and does damage electrical components, such as keypads and can also affect your weighing results as static will cause metal parts to be attracted to one another creating) Plastic is sometimes subject to breakage and can be damaged by chemicals. It is also not a stable material when stress (weight) is applied. No weighing device likes movement of the support structure, no matter how small that movemant. This is why many of the more expensive balances have a cast aluminum or steel structure, to not only provide a stable platform, but to guard against static electricity effects and to provide longevity.
Just like a gas pump, your balance reads a series of numbers, supposed to be in synch with the amount of fuel dispensed, or in the case of a balance, how much weight is applied. Just because the device reads to a division (smallest number displayed) doesn’t mean that it is accurate to that number. (Your gas pump is controlled and tested by your local weights and measures department, you balance will more likely not be.
All balances have a specification showing how close they come to absolute accuracy. You will see the following specifications.
This describes how a balance will react when a known weight is applied (usually a weight is applied 10 times to verify this specification) showing the variation in results as ±. For instance a balance reading 300 g x 0.001 g (a milligram balance) might show a repeatability figure of ± 0.003 g. This shows that the balance will repeat over the 10 weight applications, to ± 0.003 g or show perhaps on 20 g, readings of:
This balance is actually in specification for a ± 0.003 g repeatability. If the balance has a closer repeatability specification, say ± 0.002 g, then it would be out of specification.
The better the balance, generally the more you pay for the balance, the tighter the specifications and the closer the balance is liable to meet said specification. Here it might be useful to look at the difference between real diamonds and paste jewelry. Both look the same from a distance, but close up the diamond sparkles, but the paste jewelry looks dull. It is important to use the right tool for the job. We sell many different levels of balances, but to really get the best result for your money, it is important to purchase the correct level of balance. Depending on your application, you may need a tight tolerance or you may need something not so exact. Please be careful to understand that these little ± signs are very important. Readability, that is what value the balance reads in is only half the story. How accurately it reads is contained in those pesky ± signs.
All balances have a linearity specification, again described as ±.
Basically, linearity is a deviation (or no deviation) from a straight line. If we draw a graph with weight at one side and displayed value on the other, a purely linear balance would show a straight 45° line from the zero point, right up to full capacity. Each time the load increases, the displayed value increases at the exact same rate, thus giving the straight line. See Fig. 1. (Please note that the errors in the graphs below are exaggerated to provide clarity).
In Fig. 2. We see an example of the allowed linearity of an analytical balance of 200 g with an allowable linearity of ± 0.0002 g. This example shows the error allowed around the “perfect” linearity. The green shaded area represents the permissible error allowed.
Hysteresis describes how the effect of the weighing mechanism may affect the result of a weighing machine, during applying increased weight and then decreasing the weight. As the weight applied increases, the balance may read correctly “up” the range, but when you begin to remove weight, the displayed result does not return to the correct reading for the weight that is left on the platter. Many lower cost balances will weigh correctly on the way up, but suffer inaccuracies on the way down. If this error does not worry you, then perhaps you will be able to pay a little less for your balance, but if not, then this could be a serious issue for you.
Many of the cheaper balances are able to weigh effectively, especially if weighing is not done many times per minute, but these balances will not do much more for you than weigh. If you want applications capability or connectivity in a meaningful way, then the higher end balances will be more likely to fit your needs.
So, the issue of cost of a balance is complex, but the main thing to remember is that just because a balance reads to 1 gram or 0.01 g doesn’t necessarily mean the answer you will get is correct. The more money you spend on the balance, the better your results will be.
That is not really a surprise is it?
Intelligent Weighing Technology offer balances from the highest price down to reasonably low cost. Every balance we sell is value for money and how much you spend is probably in proportion to the importance of the job
Intelligent Weighing Technology will be exhibiting at the Eastern Analytical Symposium this November 17-19th. Come see us at booth #228 where we will be showing off our newest line or Precisa balances.
Pittcon is right around the corner. This years event will be hosted at the New Orleans Morial Convention Center March 8-12th. Intelligent Weighing Technology will be exhibiting there, showing our range of balances and stainless steel scales.
We recently visited ISWM Fall meetings in St Charles, Illinois September 11-13th, Central/Northwest Division Meeting.
Rich Puestow met many new dealers who were interested in the Precisa range of high end balances. Richard enjoyed the typical Mid-West hospitality that he is used to (Rich was born in Wisconsin).
The show was well attended and we will definitely attend the next one.
September 19th-21st, Richard Sharpe made the trek to Myrtle Beach South Carolina, for the South East ISWM Fall meeting. Table Top presentations from many suppliers were available in the main meeting room and again the Precisa range of balances was star of the show. Southern hospitality was in great supply over the two days and ISWM Vice President, Jerry Finnegan topped off a great weekend with his rendition of many musical favorites from the 60’s and 70’s.
Thanks to South Eastern Division for a great weekend.