At the heart of oil analysis is a spectrometer. It is the machine that allows us to quantify wear metals, additives, and contaminants in oils, making oil analysis a useful service in predicting potential problems in engines and machines of all types.

A spectrometer can be aimed at a star to determine what elements may exist in the star, if all the star’s light is being generated by the star (rather than reflected off the star). Spectrometry works on the same principle, but we have to first create the light. We do this by converting the actual oil into light energy. This is done by injecting the oil into something called plasma. You can think of plasma as a flame, since it looks like a green flame. But plasma is much hotter than a normal flame, and it needs to be in order to do its work. The plasma we use has a temperature of about 10,000° C. Plasma is actually the highest state of energy (the states of energy being solid, liquid, gas, and plasma).

Inductive coupled plasma, known in the trade as ICP, works by converting argon gas into plasma. So long as the argon pressures and flow rates don’t change, and the power causing the plasma’s generation is steady, the intensity of the plasma stays the same. This gives ICP spectrometry the industry gold star for incredible accuracy.

Seasoned travellers are well aware of the many different plugs and sockets in use around the world. 

But which plug is used where?

First-time travellers to foreign countries may only find out when confronted with the problem of trying to plug their razor or hair-dryer into a socket with an unsuitable configuration, like pounding a square peg into a round hole.

With this problem in mind, the IEC created a plug and socket zone that is both informative and practical. It explains why things are as they are today and how they might be improved. It also provides information on the plugs, sockets and voltage used around the world, along with illustrations of the various plugs and sockets available.

Extensive test data exist on the ignitability of nonmetallic materials in pure oxygen, but these
characteristics are not as well understood for lesser oxygen concentrations. In this study, autogenous ignition
temperature testing and pneumatic impact testing were used to better understand the effects of oxygen
concentration on ignition of nonmetallic materials. Tests were performed using oxygen concentrations of 21,
34, 45, and 100 %. The following materials were tested: PTFE Teflon®, Buna-N, Silicone, Zytel® 42,
Viton® A, and Vespel® SP-21.

The hazards of oxygen and oxygen-enriched mixtures Oxygen-enriched classification In the United States regulations define oxygen-enriched mixtures or atmo-spheres as those containing more than 23.5% oxygen by volume. In oxygen-enriched atmospheres, the reactivity of oxygen significantly increases the risk of ignition and fire.

The On-Line Encyclopedia of Integer Sequences (OEIS), also cited simply as Sloane's, is an online database of integer sequences. It was created and maintained by Neil Sloane while a researcher at AT&T Labs. Foreseeing his retirement from AT&T Labs in 2012 and the need for an independent foundation, Sloane agreed to transfer the intellectual property and hosting of the OEIS to the OEIS Foundation in October 2009.[4] Sloane is president of the OEIS Foundation.

OEIS records information on integer sequences of interest to both professional mathematicians and amateurs, and is widely cited. As of June 2019 it contains over 320,000 sequences, making it the largest database of its kind.

Each entry contains the leading terms of the sequence, keywords, mathematical motivations, literature links, and more, including the option to generate a graph or play a musical representation of the sequence. The database is searchable by keyword and by subsequence.

Plasteel provides two Excel spreadsheets, one English and one Metric, that compute the volume of liquid in a tank given the rod depth measurement. These spreadsheets produce print-ready
lookup tables that are specific to your tank’s inside length and diameter.

Ethics is our Underlying Standard, Excellence is Our Ultimate Goal.

Technical Papers and Letters on various piping topics

I would like to know what the term "passivated" means related to metal finishing.

"passivated" to me, means a zinc surface has been treated with a hexavalent chrome compound. The purpose of the passivation is to increase the amount of time before corrosion of the zinc begins. Some examples of zinc surfaces would be zinc die cast parts, galvanized steel sheet stock, or electrogalvanized sheet stock.

Another definition of passivated implies the protective oxide layer on stainless steel has been restored or regenerated after the parts have been fabricated or welded.

'Passivated' essentially means 'de-activated'. It doesn't have just a single meaning as a surface finish, however. Two very common meanings refer to the treatment of stainless steel in nitric acid or other materials to make it less prone to rusting, and the application of a chromate conversion coating to zinc or cadmium plating.

But there are other meanings too. For example, nickel anodes can become passivated, which is a bad thing rather than a good thing, because the anodes won't dissolve into the plating solution and it will run out of nickel.

There is a good explanation of passivation in ASTM A967 [link by ed. to spec at TechStreet] .

Passivation of stainless steel is basically the removal of exogenous materials and iron from the surface, thereby "chromium enriching" the surface. This is followed by oxidation of the chromium to form a corrosion resistant layer of chrome oxide on the surface. There are various ways to do this, as explained and detailed in that .

As an example, you can take 316L stainless steel, which is 18% chromium, and by passivating the surface reach up to 90% chromium in the surface layer. This chromium oxide layer is much more resistant to corrosion than the original surface.