Weighing


Plant service vehicles, loading and weighing devices  [c.418]

Absorbing the gas on a substance which can be weighed both before and after absorption.  [c.186]

Gouy balance A balance for the determination of magnetic susceptibility. The sample is weighed in and out of a magnetic field and the susceptibility is calculated from the difference in weights.  [c.195]

The normal form in which nickel is weighed in analysis. There is metal-metal bonding in the solid. The red complex is precipitated from alkaline solution.  [c.273]

Regnault s method Obsolete method for determining gas densities by direct weighing of a known volume of gas under known conditions of temperature and pressure.  [c.343]

With regard to hydrogen, the accuracy is deemed insufficient for obtaining the hydrogen balance in a refining process. A rather cumbersome answer used at times is to determine the content by macro analysis. The hydrogen content in approximately one gram of sample is calculated by weighing the water formed. More recently, a totally different technique has appeared, hydrogen analysis by nuclear magnetic resonance. Refer to article 3.2.2.2. The order of magnitude of the absolute error is 0.05%.  [c.29]

To obtain satisfactory burner operation without forming deposits and with minimum pollutant emissions, heating oil must burn without producing residues. This property is expressed by a value called Conradson Carbon (NF T 60-116). It is obtained by recovering the heaviest distilled fraction of the sample (greater than 90 wt. % distilled, i.e., about 10 wt. % of the feed) and subjecting it to pyrolysis in a crucible at 550°C for thirty minutes. The residue is weighed and the Conradson Carbon is expressed as a weight per cent of the sample.  [c.234]

The procedure most commonly employed (NF M 07-047 or ASTM D 2274) Is to age the diesel fuel for 16 hours while bubbling oxygen into it at 95°C. The gums and sediment obtained are recovered by filtration and weighed. There is no official French specification regarding oxidation stability however, in their own specifications, manufacturers have set a maximum value of 1.5 mg/100 ml.  [c.247]

Insolubles content NF M 07-063 Filtration and weighing  [c.448]

Sediments NF M 07-010 ISO 3735 ASTM D 473 Extraction with toluene and weighing of residue  [c.450]

Solubility (bituminous products) NFT 66-012 ASTM D 4 Dissolving, filtration, weighing  [c.450]

A slim hole rig weighs about one fifth of a conventional rig and its small size can open new frontiers by making exploration economic in environmentally sensitive or inaccessible areas.  [c.52]

The legs of the platform can be used as settling tanks or temporary storage facilities for crude oil where oil is exported via tankers, or to allow production to continue in the event of a pipeline shut down. The Brent D platform in the North Sea weighs more than 200,000 tonnes and can store over a million barrels of oil. Topside modules are either installed offshore by lift barges, or can be positioned before the platform is floated out.  [c.266]

A rugged, powerful instrument in a cast aluminium case Weighs 6 kg including standard D cell batteries  [c.323]

The sulphate ion is detected by addition of barium chloride in the presence of hydrochloric acid a white precipitate of barium sulphate is obtained. The same test can be used to estimate sulphate, the barium sulphate being filtered off, dried and weighed.  [c.304]

Iodine is a dark-coloured solid which has a glittering crystalline appearance. It is easily sublimed to form a bluish vapour in vacuo. but in air, the vapour is brownish-violet. Since it has a small vapour pressure at ordinary temperatures, iodine slowly sublimes if left in an open vessel for the same reason, iodine is best weighed in a stoppered bottle containing some potassium iodide solution, in which the iodine dissolves to form potassium tri-iodide. The vapour of iodine is composed of I2 molecules up to about 1000 K above this temperature, dissociation into iodine atoms becomes appreciable.  [c.320]

Addition of silver nitrate to a solution of a chloride in dilute nitric acid gives a white precipitate of silver chloride, AgCl, soluble in ammonia solution. This test may be used for gravimetric or volumetric estimation of chloride the silver chloride can be filtered off, dried and weighed, or the chloride titrated with standard silver nitrate using potassium chromate(VI) or fluorescein as indicator.  [c.348]

Asymmetry in a similarity measure is the result of asymmetrical weighing of a dissimilarity component - multiplication is commutative by definition, difference is not. By weighing a and h, one obtains asymmetric similarity measures, including the Tversky similarity measure c j aa 4- fih + c), where a and fi are user-defined constants. The Tversky measure can be regarded as a generalization of the Tanimoto and Dice similarity measures like them, it does not consider the absence matches d. A particular case is c(a + c), which measures the number of common features relative to all the features present in A, and gives zero weight to h.  [c.308]

The difficulties of working with small quantities of liquids are much greater than with small quantities of solids. For example a competent worker can, and does in fact, often work with 100 mg, of solid without any special apparatus. With liquids this is often not practicable because of the much greater losses entailed, particularly when it is realised that one ordinary-sized drop weighs about 50-100 mg. The account which follows gives details of modifications of standard apparatus suitable for the semi-micro scale defined above.  [c.59]

Note. The sodium hydroxide must be accurately weighed out, for an excess will dissolve the oxime as the sodium derivative.)  [c.94]

Then filter the ethyl bromide through a small fluted filter-paper directly into a 60 ml. distilling flask. Fit the flask with a 100° thermometer, and a water-condenser having as before an ample supply of cold water then arrange the condenser so that its lower end enters the neck of a small dry weighed conical flask, supporting the latter in line with the condenser, and chilling it externally by a mixture of ice and water. Distil the ethyl bromide slowly from a water-bath, and collect the fraction boiling between 35° and 40°. Average yield, 23 g. In view of the low boiling-point of the ethyl bromide, it should be preserved in a sealed glass specimen tube (see Fig. 21, p. 41).  [c.102]

After boiling for 30 minutes, the distillation of the amine may be considered complete. Concentrate the hydrochloric acid solution by placing it in a 250 ml. distilling-flask connected with a water-condenser, and distilling carefully until about 30 ml. remain. Then transfer this residual solution to a small evaporating-basin, and evaporate to dryness on a boiling water-bath. (Yield of crude dry material, about ii g.) Rapidly break up the dry solid (which consists of methylamine hydrochloride together with a small amount of ammonium chloride), and transfer it without delay to a 150 ml. round-bottomed flask fitted with a reflux water-condenser. Add about 60-70 ml. of absolute ethanol (in which ammonium chloride is insoluble), and boil the mixture for 5 minutes. Then pour the hot supernatant liquid quickly through a small fluted filter-paper into a conical flask. Again extract the undissolved residue with a further 20 ml. of absolute ethanol, and cool the united ethanolic filtrates colourless crystals of methylamine hydrochloride separate out. Filter off the crystals at the pump, and, since they are deliquescent, transfer them quickly to a weighed bottle or specimen-tube the methylamine hydrochloride m.ay be finally dried by placing the tube in a desiccator. The yield of the recrystallised material should be about 5 g. if the ethanolic filtrate from this first crop is concentrated by distillation to about 20 ml. and then cooled, a second crop of methylamine hydrochloride, weighing about 3 g., can be similarly isolated.  [c.129]

Filter the mixed product at the pump, and wash it well with ethanol to remove excess of dimedone, and then with water and again with ethanol. The dried white residual methylene-dimedone , m.p. 186-188°, weighs o 55-o-65 g. It may be recrystallised from ethanol containing about 10% of water, and then has m.p. 189°.  [c.146]

Quantitative analysis is the estimation of the amount of element or group present in a mixture or compound. This is done by various methods, in volumetric analysis a titration, in gravimetric analysis a precipitation followed by a weighing, in colorimetric analysis the estimation of a coloured species. Other quantitative methods include infra-red spectroscopy, estimation of the opalescence of a precipitate (turbidimeiry, nephelometry and fluorimetry), estimation of optical rotation, electrolytic decomposition, potentiometric, conductometric and amperometric titrations, and polaro-graphy. Organic quantitative analysis is generally carried out by physical methods or by conversion to known derivatives which can be estimated by weighing or by titration, anaplerotic sequences Ancillary routes to the catabolic cycles in organisms, which operate to maintain levels of intermediates in these cycles despite tapping off for anabolic purposes. An example is the glyoxylate cycle. Anaplerotic sequences are most obviously seen in micro-organisms where rapid biosynthesis occurs from simple carbon compounds.  [c.34]

The existing gum content (NF M 07-004) is obtained by evaporating a 50 cm fuei sampie piaced in a constant temperature bath at 160°C while subjected to a stream of air for 30 minutes. After evaporation, the residue is weighed giving the unwashed gum content. An extraction with heptane foliows which leaves only the existing gums. The French specification concerns existing gums after washing and sets the upper limit at 10 mg/100 ml.  [c.242]

Conradson carbon NFT60-116 ISO 6615 ASTM D 189 ASTM D 4530 ISO 10370 Weighing after combustion then pyrolysis Micro method  [c.447]

For onshore operations various types of landrigs are available, ranging from truck mounted light rigs to heavy landrigs weighing several hundred tons.  [c.32]

Concrete or steel gravity based structures can be deployed in similar water depths to steel jacket platforms. Gravity based platforms rely on weight to secure them to the seabed, which eliminates the need for piling in hard seabeds. Concrete gravity based structures (which are by far the most common) are built with huge ballast tanks surrounding hollow concrete legs. They can be floated into position without a barge and are sunk once on site by flooding the ballast tanks. For example, the Mobil Hibernia Platform (offshore Canada) weighs around 450,000 tonnes and is designed and constructed to resist iceberg impact  [c.266]

The prime global authority is the International Maritime Organisation. The IMO sets the standards and guidelines for the removal of offshore installations. The guidelines specify that installations in less than 75 meters of water with substructures weighing less than 4,000 tons be completely removed from the site. Those in deeper water must be removed to a depth of 55 meters below the surface so that there is no hazard to navigation. In some countries the depth to which structures have to be removed has already been extended to 100m.  [c.365]

XVn). This method requires the use of a powdered sample (to have sufficient adsorption to measure), and inteiparticle capillary condensation grossly distorts the isotherms at pressures above about 0.9/ [165]. Also, of course, contact angle data are generally for a smooth, macroscopic surface of a solid, and there is no assurance that the surface properties of the solid remain the same when it is in powdered form. More useful and more reliable results may be obtained by the gravimetric method (see Chapter XVII) in which the amount adsorbed is determined by a direct weighing procedure. In this case it has been possible to use stacks of 200-300 thin sheets of material, thus obtaining sufficient adsorbent surface (see Ref. 166). Probably the most satisfactory method, however, is that using ellipsometry to measure adsorbed film thickness (Section IV-3D) there is no possibility of capillary condensation effects, and the same smooth and macroscopic surface can be used for contact angle measurements. Most of the data in Table X-2 were obtained by this last procedure the corresponding contact angles are for the identical surface. In addition to the values in Table X-2, Whalen and Hu quote 5-7 ergs/cm for n-octane, carbon tetrachloride, and benzene on Teflon [167] Tamai and co-workers [168] find values of 5-11 ergs/cm for various hydrocarbons on Teflon.  [c.370]

A second general type of procedure, due to McBain [29], is to determine n by a direct weighing of the amount of adsorption. McBain used a delicte quartz spiral spring, but modem equipment generally makes use of a microbalance or a transducer. An illustrative schematic is shown in Fig. XVII-6.  [c.616]

Diamonds are found in South Africa, India, South America and Russia. The largest ever found was the Cullinan diamond which weighed about 600 g. The structure is as shown in Figure 8.2. (There are four possible crystalline arrangements all of which are found to occur naturally.) The interatomic bonds are very strong (mean thermochemical bond energy 356kJmor ). This high bond strength is reflected in the great hardness and high melting point of diamond. Diamond also has a high refractive index and is the densest form of carbon (density 3.5gcm ). The many uses of diamond are largely dependent on its great hardness, for example for cutting and grinding.  [c.164]

Addition of calcium nitrate solution to a fluoride gives a white precipitate of calcium fluoride, CaFj. If the latter is precipitated slowly, it can be filtered off and weighed to estimate the fluoride. Fluoride can also be determined by the addition of sodium chloride and lead nitrate which precipitate lead chlorofluoride, PbClF. This is filtered off and weighed.  [c.348]

A standard solution of potassium dichroinate can be made up by accurately weighing the pure salt. (A standard solution of potassium manganate(VII) cannot be made up by direct weighing, since the salt always gives a little manganese(IV) oxide in water.) Sulphuric acid is added to the solution to be titrated, but hydrochloric acid can be present, since the chloride ion is not easily oxidised by dichromate [cf. manganate(VII)]. The end-point is not easy to detect with dichromate, since the orange colour of the latter has merely been replaced by the green colour of the hydrated Cr " ion. It is therefore usual to use an oxidation-reduction indicator, such as diphenyl amine, which turns from colourless to blue at the end point.  [c.379]

Gold compounds are all easily reduced in alkaline solution to metallic gold which may occur in colloidal form and so be red, blue or intermediate colours. Reduction to gold, followed by weighing of ihe metal precipitated, may be used in quantiiaiive analysis.  [c.432]

Weighing and measurements. The rough balances used for macro-scale preparative work are not adequate for senu-micro preparations. For the latter purpose, ordinary analytical balances should  [c.69]

Acetamide is thus obtained as a colourless crystalline solid, which has a characteristic odour of mice, stated to be due to the presence of small quantities of methylacetamide, CH3CONHCH3. The acetamide can be purified and rendered odourless by re-crystallisation from acetone, and then has m.p. 82°, b.p. 223°. If this recrystallisation is contemplated, the distilled material should be collected directly into a small weighed beaker or conical flask, so that the solidified acetamide can be readily broken up and removed.  [c.118]

In view of the great avidity of phosphorus pentoxide for water, the apparatus used in this experiment should be assembled before the pentoxide is weighed out. Fit a 500 ml. bolt-head flask to a water-condenser (see Fig. 59, p. 100). Disconnect the flask, then twist some glazed paper into the form of a cone, and push the narrow end of the latter (slightly opened) into the neck of the flask. Using a rough balance, weigh out on pieces of glazed paper first 20 g. of dry acetamide, and then (as quickly as possible) 35 g. of phosphorus pentoxide. With the aid of a spatula, tip the pentoxide without delay down the paper cylinder into the flask, then add the acetamide similarly, remove the paper, and at once cork the flask and mix the contents by gentle shaking. (Before throwing away the paper used for weighing the pentoxide, wet it thoroughly, otherwise residual pentoxide may cause it to smoulder and possibly inflame.) Now heat the flask by direct application of a Bunsen burner, using however a luminous smoky flame, and applying it uniformly over the bottom of the flask. The acetamide melts and then the  [c.121]

From a clean, dry stick of zinc chloride, break off a piece weighing roughly i g., crush it quickly into coarse fragments in a mortar, and then add it to 25 ml. of acetic anhydride contained in a 100 ml. round-bottomed or conical flask. (Owing to the very deliquescent nature of zinc chloride, this manipulation must be carried out as rapidly as possible hence have both the acetic anhydride in the flask, and the mortar available near the balance, before the zinc chloride stick is withdrawn from the stock bottle.) Fit the flask with a reflux water-condenser and heat the mixture of zinc chloride and acetic anhydride on a vigorously boiling water-bath for about 5 minutes until the maximum temperature is reached and nearly all the chloride has dissolved. Now remove the condenser and add 5 g. of powdered glucose (anhydrous or monohydrate) cautiously to the acetic anhydride, shaking the mixture around occasionally during the addition, in order to control the vigorous reaction which follows. Finally replace the condenser and heat the mixture for i hour on the water-bath, and then pour the liquid into about 250 ml. of cold water. The latter should preferably be cooled externally with ice-water, and be stirred vigorously during the addition of the acetylated product. A viscous oil separates at the bottom of the beaker, and if occasionally stirred will crystallise within about 10 minutes. After solidification of the oil, allow the mixture to stand for a further 15 minutes, and then filter at the pump. If any large lumps of the crude acetyl compound have formed, transfer them to a mortar, pulverise, and then wash them back into the Buchner funnel. Finally wash the product on the filter thoroughly with water, and drain. (Yield of crude material.  [c.141]


See pages that mention the term Weighing : [c.50]    [c.70]    [c.196]    [c.250]    [c.328]    [c.40]    [c.328]    [c.1025]    [c.1911]    [c.202]    [c.276]    [c.118]   
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