Test weight

Because of the extreme accuracy expected of many of these products, some include internal test weights which can be used to recaUbrate regularly and to adjust for nonlinearity. Some balances monitor changing conditions and initiate the recahbration procedure as needed. 

Shift error, the range of results obtained when a test weight is moved around the scale platform in a specified manner (5), expressed as a percentage of scale capacity... 

Using an equal-arm balance (see Fig. 1), the unknown mass of an object can be deterrnined by placing it ia one pan, and adding test weights to the other until the beam balances. The result wHl be the same regardless of location because the object and the test weights ate subject to the same value of. Any scales that measure an unknown mass by comparing it with a known mass (with or without a lever system), wHl be unaffected by variations in g. 

Some scales have a software feature whereby a certain geographical region is identified on initial configuration, and the software then makes the appropriate correction. Some high performance balances have built-in test weights for initial (and periodic) calibration. 

Buoyant Effect of Air. Weighing operations performed m vacuo are not affected by buoyancy forces. An object in air, however, is subject to a buoyancy force that is equal and opposite to the gravitational force on the mass of air the object displaces (10). If the equal arm balance of Figure 1 is in balance with a test weight of mass, in one pan, and material of mass, m, in the other, m = m if they have the same density. If the densities are different, then the buoyancy forces acting on each pan affect the result. Taking moments about the center pivot point gives... 

Test weight = (gross vehicle weight rating + crub weight)/2. 

Reduced weight has been a major contributor to the improvements in performance and fuel economy over the twenty-year span of Figure 6. From 1975 to 1980 the test weight of the average new passenger car fell nearly 25 percent. It has crept up slowly in the following fifteen years, but in 1995 was still 20 percent less than in 1975. The trend from rear-wheel to... 

Test Weight of Charge, Weight of Charge, Detonator 90/10 MF/K chlorate PETN/LA... 

Anemia, increased liver enzyme activity, increased cholesterol and urea Decreased body growth decreased testes weight... 

Reduction in testes weight and spermatozoa number. No effect on egg production or fertility. Bone lead levels higher than controls especially in females. Significantly higher lead concentrations in bone, liver, and feather in progeny of lead-treated parents than in controls... 

Not only is it difficult to detect effects on male fertility because of group-size considerations, effects on male fertility mediated by decreased sperm production are also difficult to detect because of the normally huge excess of sperm included in a rat ejaculate. Sperm production can be decreased by up to 90% without effect on fertility (either pregnancy rate or litter size) in the rat. This is not the case for men, so the sperm excess in the rat represents a serious flaw in the rat model (see Working, 1988). To address this deficiency and improve the sensitivity of the model, it is advisable to determine the effects of the test agent on testes weights, testicular spermatid counts, and histopathology of the testes (preferably plastic sections) in the male fertility study and/or the 14-week toxicity study. In some cases, these parameters may be more predictive of possible effects on male fertility in humans than the fertility rate in rats. 

Rat (Sprague- Dawley) 90 d 1 x/d (G) 4.35 14.5 (increased testes weight) Gerhart 1987a CuCN... 

Determination Test, Weight loss test, Eschke test, Salt spray test and Sulphur dioxide test at 50°C. Mechanism of inhibition of corrosion and surface study of mild steel was also studied by Metallurgical Resesarch Microscopy and Scanning electron Microscopy. 

Okino etal. (2003) tested composites manufactured from acetylated rubberwood bonded with UF resin against G. trabeum and T. versicolor. In the 12-week exposure test, weight losses were found to considerably less than exhibited by control samples. 

Yusuf etal. (1989) exposed IS- or PF-bonded particleboard made from acetylated albizzia to C. formosanus according to JWPA standard 12-1981, and in a field test (3 months exposure next to a nest of Coptotermes sp.). In both tests, weight losses were around 50 %, indicating a lack of resistance to attack by this species. 

Inhalation of diesel fuel aerosol 4 hours/day, 2 days/week, for 13 weeks at concentrations up to 1,500 mg/m did not induce relative testes weight changes nor histopathological changes in the reproductive organs of rats (Lock et al. 1984). 

Fertility and early embryonic development (rat). Provided no deleterious effects have been revealed by testicular histopathology assessment and testes weight measurements (ICH guideline. 

Allyl chloride was fetotoxic to rats exposed during gestation to 300ppm, which also caused considerable maternal toxicity in the form of kidney and liver injury. It was a testicular toxicant in mice, causing decreased testes weight, reduced numbers of spermatids, and increased frequency of abnormal sperm after a single subcutaneous injection to male mice at one-fifth the LDso. ... 

Reduced testes weights and histologic evidence of testicular injury were found in rats and guinea pigs but not hamsters or mice fed 2g/l /day DBP for 10 days, indicating a species-specific response. The basis of this species variation may be related to species differences in the ability to conjugate monobutyl phthalate, the primary metabolite of DBP, with glucuronic acid. ... 

Oral administration of lOOOmg/kg by gavage to male rats for a total of 12 treatments over 16 days caused reduced testes weight and increases in abnormal sperm heads. ... 

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