Reference marks

Einstell-lupet /. focusing lens, -marke, /. reference mark, -schraube,/. adjusting screw. Einstellung, /. putting in, standardization, etc. (see einstellen) reference standard (of a solution),... 

With this tension on the drillstring, a reference mark is made on the drillstring exposed at the top of the rotary table. 

A larger upward force F is then applied to the drillstring. This causes the free portion of the drillstring to elastically stretch by an amount L (ft). The stretch (or elastic displacement) is measured by the movement of the original reference mark. The magnitude of F is limited by the yield, or elastic limit of the pipe steel. 

Establish a reference mark on the shaft or sleeve flush with the face of the stuffing box. 

This dimension added to the distance the insert extends into the stuffing box will give the seal setting dimension from the reference mark on the shaft or sleeve to the back of the seal collar. 

You may find the following references useful in getting the information you need to identify and control reactivity hazards. References marked with an asterisk ( ) can be obtained from the American Institute of Chemical Engineers - Center for Chemical Process Safety, 1-800-AIChemE, www.aiche.org/ ccps/products. 

The compressibility of solutions are determined by measuring the volume change of Hg in the capillary when various pressures are applied to the system. The change in height of the meniscus (Ah) and the pressure change (AP) are dependent upon the volume of mercury (VHg), the volume of the solution (Vg0 n), and the inside volume of the glass container to a reference mark (Ah). 

This chapter is about molecules. A molecule is a collection of nuclei Z., Z/,... at rest (in the Bom-Oppenheimer approximation) in a sea of fast-moving electrons. The nuclei can be identified and thus provide convenient reference marks. Each nucleus found in the molecule, say, Z], can be viewed as the nucleus of a giant atom extending over the entire molecule is surrounded by charges, just as in an ordinary atom, with the difference that motionless positive point charges are now part of its environment. Of course, the electronic content is still described by its stationary density. 

The basic method is to use a manual Abbe refractometer to determine refractive index. Various automated or electronic instruments exist which automatically perform some of the steps of the manual procedure. The first requirement is that the sample be a solution. In some instruments, the solution is placed between two prisms, and the image of the critical ray boundary is adjusted to meet a reference mark for this adjustment, the refractive index and equivalent °Brix can be read from a scale. The sample temperature must be known, or the instrument must have temperature compensation. Some automatic digital refractometers use the same methodology of sample presentation, but automate the matching of the critical boundary to the reference marker. 

Fig. 4.1 Depth of water table AC is the depth below the reference mark at the edge of the casing BC is the depth below the surface.

U-tube, 4 mm. i.d. and 10 cm. long, was used for the density measurement. The volume of the U-tube was determined as a function of the distance from a reference mark at the bottom of the tube. Calibrations were made at room temperature, initially with water and carbon tetrachloride, and again at cryogenic temperatures with liquid oxygen. A measured amount of liquid ozone was transferred to the U-tube, and the procedure was repeated with enough liquid fluorine to result in a solution of the desired concentration. 

For samples that cannot meet the requirements for the UL 94 V test, the UL 94 HB horizontal burn test is a possibility. Flame spread in the horizontal orientation is much slower than for the vertical test. Two marks are made on the bar at 25.4 and 101.6 mm from the free end of the specimen. After the flame has been applied for 30 s, the burn rate between the reference marks... 

Each axis must have a scale with reference marks ( tics ) on the axis to show clearly the location of all numbers used. 

References marked with are reprinted in this volume. 

Initially, a sample cell was half-filled with surfactant solution by capillary action. Next, the cell was sealed at the bottom and attached to a microscope slide with fast-setting epoxy. If movement of interfaces was to be measured, a reference mark was placed next to the capillary near the meniscus. 

You should get sin idea about how high in the pipet 0.5,1.0,1.5, and 2.0 ml of liquid are. Just draw measured amounts into the tube and look. I d mark one pipet with all these volumes and keep it as a reference. Marking your working pipets can get messy, especially when the markings dissolve into your product. And scratching a working pipet with a file is asking for trouble. Get the scratch wet, a little lateral pressure and—snap—that s the end ofthe pipet. 

There is some confusion in the CAS registration concerning compounds 70 and 71. For the registration number 31148-63-7 there are three references marked, two (99 and 120) for compound 70 and one (124b) for compound 71. Apparently, these two compounds are erroneously presentedasoneand the same compound. 

There s generally a mark right up by the stopcock or just below the connecting tube, which indicates a measuring place. Look at those absorption tubes and see if you can find a little reference mark. If not, then pick some reference point that you can use for adjusting the solution level. 

Pnnti ng.) A character (t) to call attention in the text to notes on the foot or margin of the jiage. As a reference-mark it comes next after the star ( ). 

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