Once you get comfortable operating your model railroad, you will begin to notice the little defects and problems with your setup. We are always sensitive to derailment. Here are some tips about track and ballasting, and they are useful to review whether you are a novice or an old-timer. ™ HO Track The various track manufacturers have made a large variety of track length and radii sections over the years. I like to keep as many variations in my "stock" as I can, to make it easy to construct a layout in a given space. With all the various "Code" styles, this can get complicated. Track Codes The standard 16.5mm HO track with a rail height of 0.100in (2.54mm) is known as "Code 100" track. There are other Code sizes as well. A rail section height more to scale is Code 83, and for finescale modelers there is Code 75 track. Flexible Track Flexible track comes by the yard or metre, and can be used to make layouts that closely follow a prototype's transitions. Flexible track can be cut with a razor saw, or special rail cutters. All of the flexible tracks have some way to attach them to the roadbed, either with holes in some ties (sleepers) or 'blind' holes that can be punched out. Spikes, Pins and Tacks The type of hold-down you use for your track depends upon your roadbed material. Pins work well with any type of soft board, while spikes can be used with MDF or soft board, and tacks are best for plywood or thick MDF. You may get better results with thick roadbed by drilling a pilot hole and then pushing the tack in with pliers. Rail Joiners All those sections of track must be joined together properly, or you may have poor electrical connections or derailment. It's a real hassle to find out two sections are not joined properly after you have pinned down all your track. Make a test run prior to pinning whenever you are laying track. Realistic Track Has That Weathered Look Weathering track, sleepers and ballast will add that fine detail that can really make your model railroad stand out. For Rainin tips larger layouts, weathering may be best done prior to laying track, while smaller layouts, where you can get at everything easily, could be done after pinning the track down. Paint colors to use range from black to burnt umber and other reddish-brown colors. "Track colors" are available as well. A small brush and some time are all that's needed to weather your track. Make sure you hit the sleepers as well. Don't worry about getting paint on the top of the track. Just let it completely dry, and then use a track rubber to clean the tops off. Keep paint out of rail joiners and moving parts of turnouts. Ballasting Track You may think that ballasting track is a messy job, and not worth doing. Au contrare, my friends. Ballasting can be simple and clean, and worth the time and effort into making your layout realistic. If you really don't want to get into it, then start off by purchasing pre-made ballasted track. Using pre-made ballasted track may cost more up front, however, there is the savings in time and hassle over doing it yourself. Additionally, these tracks are quite sturdy, and should last a long time, again offsetting the initial cost. Take the time to weather your pre-made ballasted track though. Detailing it now will overcome any objections to your track looking like a toy. There's lots of makers of ballasted track, including Fleischmann, Roco-Line, Bachmann, Kato and others. Do It Yourself Ballasting For the die-hard, ballasting your track by hand is the only way to go. Here's some simple techniques to get you started. What's important is to take your time when doing this, and you will have a realistic track that meets the standards of even the most critical observer! The overall technique is to have your track all pinned down (and tested to ensure there's no derailments). You then add the ballast material around the track. You can use a brush to move it around and get it where you want it. Prepare a wetting agent consisting of a few drops of dish soap in water, in a spray bottle. Make your bonding glue by diluting white glue with water, about 20:1 ratio. Next you will wet down a section of track at a time by spraying the wetting agent on it. This is to help your glue flow into all the little cracks and crevices in your ballast. Using a straw as a pipette, you then pick up some of your glue solution and drop it along the centerline of the track section that you wet down. Do this for your whole layout, and let it dry for 24 hours. This glue will be transparent when it drys. Take care when gluing ballast around turnouts and other moving parts. Note that you can also place weeds or other debris among the ballast prior to gluing, and the glue will then hold all that in place as well. And, this method of gluing can also be used to hold down scenery throughout your layout, not just the ballast. Store-Bought Ballast Don't want the hassle of ballasting yourself. Don't want to purchase pre-ballasted track? Ok, then how about these two alternatives? Tracklay is an adhesive strip that you lay your track on, and then press ballast in place around it. Brush-it-On comes in packs of various scales. You just add water, and apply the mix with a brush or a spatula. This can be as messy as it sounds, however, when done properly can look very good. Pipettes are laboratory instruments/tools used to transfer liquids, usually chemicals from one place to another. They are used very extensively in experiments that involve reactions of acids and alkalis, so known as titration experiments. Accuracy is one of the salient features of these tools and they come about owing to many features. One of these is the precise calibration of the tube that allows accurate markings and liquid capacity to be noted. Another feature is the pipette filler that is available separately but from the same manufacture that one may decide to buy the tube from. These allow safe and accurate filling of any chemical. A very important sub instrument available with this is the pipette tip that is places towards the end or suction area of the tool and helps in accurate and easy injection of fluids. Pipette tips are disposable. This is good news for many users as a lot of experiments do require the use of the tools without a protrusion. This will help flexibility with which scientists and chemists can perform experiments. Although the user may buy any form of tip they want, but experts highly recommend that it be bought from the same manufacturer they got the pepittor from as it will fit in properly as required and will also be of the desired accuracy. The manufacturer can also guarantee or offer a warrantee offer on any items that may be returned in case they do not work as advertised. Pipette tips are available in many sizes and forms. They can be available in sizes depending on the size of the tool they have to be attached to. So for instance if the tube is wider in diameter, the tip will be made accordingly. This is exactly why experts ask for the same manufacturer's pipette and tip, because they fit together more effectively. They are prepared in sizes exactly the same as the pipettes are manufactured in order to ensure perfect functionality. The varieties that these tips are available in include sterilized, non-sterile and filtered tips. They come in five together in a single tray. The sterilized variety is actually more common in experiments that involve the use of medicine and vaccine. Also when the study of blood is involved, all possible care needs to be taken to ensure that pathogens and bacteria do not contaminate the culture or whatever experiment is under study. Filtered variety is used to extract liquid that contain tiny solid particles for example a mixture of sand and water. The filter acts as a permeable layer that leaves out any unnecessary particles. A non-sterile form is the simplest form of tip that is available. It is the cheapest too, given that no extra work is put into it. The tip works fine for regular experiments and all kinds of liquid. The tips are made of hard or good quality plastic. The reason for that is that plastic is a non reactive matter so it does not alter any acids or alkalis. The tips are also made of part plastic, part glass or even rubber. These also ensure that the tip flexibly fits the tube without breaking and it also ensures that it is fit in tight. The introduction of these extras has made experimentation a lot easier compared to earlier times along with this experimentation has become a lot safer as well. It has allowed experimenters and many other to use precision and transfer their liquids under study to small areas. The nozzles of the tips allow the liquid to escape but not too quickly allowing more control and precision.
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Ensuring quality data collection is absolutely vital for the success of any science experiment, especially chemistry. Lab equipment such as Erlenmeyer flasks, test tubes, scientific balances, and beakers hold chemical reagents and the product of major reactions. Because the reactants and products in a chemical reaction must be carefully weighed and balanced for later analysis as well as the fact that certain reactions are difficult to instigate and maintain keeping glassware and other laboratory instruments free of contaminants is essential. Proper care of science lab equipment, especially chemistry lab equipment, is an essential skill for any modern day physical scientist. ™ The most basic essential step to ensure that lab equipment is free of contaminants is to rinse any item used, whether before or after the beginning of an experiment, with deionized water. Using DI water to clean chemistry lab equipment is important because it is free of electric charge and has a relatively neutral pH. Water that is not DI that clings to the side of glassware will likely alter the pH of added solutions and introduce systematic error into later calculations. Any lab instruments that have been rinsed should be carefully dried using a towel that will not shed or leave any other residue - just remove the excess water from the instrument. Science laboratory equipment is broken all too often, but worse is when it is handled roughly or stored improperly and develops hidden cracks or chemical films. Many chemistry experiments require the use of strong acids and bases that must be contained in glassware. If they are exposed to skin they can cause serious burns. Glassware that has developed hidden cracks is prone to breaking when filled with a solution or bumped in the course of running an experiment and this breakage can lead to dangerous compounds spilling and splashing onto exposed skin. Science lab equipment improperly cleaned or stored can also be contaminated with chemicals that will undergo unwanted side reactions during an experiment, throwing off the validity of any results obtained. Proper storage and maintenance of laboratory instruments is of utmost importance and fairly simple. When not in use, store all glassware and instruments in a sturdy closed cabinet. When handling them, use firm but gentle grips and move slowly and deliberately. Clean before and after experiments by rinsing with deionized water. And of course use the instrument that is best for the job. Trying to pour liquid into a buret without a funnel can lead to awkward movements, spilled chemicals, and broken laboratory instruments. The pipette, the most commonly used equipment in laboratories for extracting the samples. It is mainly used for transferring liquids or semi-solids on laboratories. It's really interesting to know the working and internal mechanism of pipettes. The pipette should be adjusted so that the dispensed volume will be within the required specifications. The pipettes can be mainly classified into two Air Displacement Pipettes and Positive Displacement Pipettes. Air Displacement Pipettes - These types are called as air displacement pipettes because a certain volume of air remains between the piston and the liquid. These are only used for general purpose with aqueous solutions. • There is a Rainin Pipette Tips piston inside the pipette which will be moved to appropriate position when the volume is set. • Piston will expel the same volume of air as indicated on the volume setting when the operating button is pressed. • The operating button will be released after immersing the tip into the liquid, which will create a partial vacuum and the specified volume of liquid is aspirated into the tip. • When the operating button is pressed to the first stop again, the air dispenses the liquid. To empty the tip completely the operating button is pressed to the second stop. There is lot of factors like temperature, density and altitude which should be taken care otherwise it may seriously affect the accuracy of these air displacement pipettes. Positive Displacement Pipettes - It is mainly used for high viscosity and volatile liquids. The specialty of these pipettes is that the piston will be in direct contact with the liquid. The tip of it contains a disposable plunger just like a syringe, which will displace the fluid without any errors. These types are the most accurate type of pipette but the disadvantage of this one is it's highly expensive, so this not used for general purposes. There is lot of points to be remembered while using a pipette. First of all daily wipe the pipette with 70% ethanol so that there won't be dirt on the pipette. Now check whether the volume is in specified range. While holding the pipette the "grippy finger rest" should rest on the index finger. To get the maximum accuracy the pipette, tip and liquid should be kept at the same temperature. Its always better to use high quality tips which is made from contamination-free polypropylene for the pipette, so that the tip will ensure maximum accuracy. The metrological characteristics of the tips will change after each time of use so it should be cleaned after use. Its better to pre -rinse the tip three to four times with the liquid to be used. It will definitely increase the accuracy especially when using positive displacement tips. Don't turn the pipette on its side when there is liquid in the tip, liquid must go to the interior and contaminate it. Always try to store the pipettes on stands in upright position when not in use. If used daily it is recommended to check the calibration in three - month interval. Always follow the instructions of recalibration. |
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