Calibration factor

As mentioned in Section 8.3.2, the instrument must be calibrated with a substance of known molecular weight. The experimental conditions, i.e., solvent and temperature, must be strictly identical with those used for lignin samples. The calibrating substances usually employed are benzil (M = 210.2 g mol ) and sucrose octaacetate (M = 678.6 gmol ) with concentrations, m, in the range between 10 2 and 10 molkg-1. 

A plot of AR/m against m gives a straight line whose intercept at infinite dilution is K (Ohm mol-1 kg). 

Solvent Boiling temperature (°C) Operating temperature range (°C) 

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Very shortly, the first one is based on the stress measurement performed using a rosetta strain gauge located in an area of sufficiently uniform stress distribution. In this case, the calibration factor Cr can be easily obtained by the following equation ... 

On the contrary the second one does not require a knowledge of the stresses in the specimen. In this case, the calibration factor is determined by known test material properties and SPATE equipment characteristic data into the equation ... 

The calibration curve of each rosetta strain gauge was so obtained and ftg.5 shows the sum of the principal stresses at the measuring points versus pressure inside the vessel. Further tests were carried out to obtain the calibration factor and to check that it remained constant on the whole scan area of the test surface. This was achieved through additional measurements using the SPATE system on fixed points on the surface located very close to the applied rosetta strain gauges. This procedure gave the following results ... 

Since the known stress calibration method was adopted to perform the SPATE setting, the calibration factor was directly obtained from the preliminary tests above mentioned. However, it is interesting to observe that assuming the correction factor equal to 1 at 10 Hz, the ratio of Cf at the others investigated frequencies (2 and 5 Hz) to the calibration factor at 10 Hz gives ... 

Since the calibration factors for these techniques are known and relatively stable (depending on constant optical and geometrical parameters), the calibration process for laser-based measurements is simple or can be ignored. 

Table 4.2. Calibration factors for quartz and lithium niobate gauges.

It is gratifying that no empirical calibrating factor was needed with the Fe-55 source, which means that the results were predictable from Equation 5-6 by insertion of accepted values for the mass absorption coefficients. The deviation corrected by the introduction of this empirical factor (Equation 5-7) was of the kind produced by the filtering of polychromatic beams. About all that can be said about such empirical factors and about background corrections is this Always unwelcome, not to be introduced unless necessary, the need for them does not in itself make a method less desirable, but it does usually indicate that something is incompletely understood. 

Absorbance Reading [AU] Tablet Weight [mg] Assay [mg] Calibration Factor Type of Result... 

The homopolymers of styrene and acrylonitrile were not soluble In the acetonitrile mobile phase. Calibration factors thus had to be derived from a combination of literature data and experimental measurements. To calibrate the UV detector for polystyrene, 254 nm absorbance of both monomer and polymer was measured with a conventional spectrophotometer, using chloroform... 

To allow for this, before the peak areas are normalised we must first correct each area so as to get the area we would have obtained had the detector response been the same for each of the three compounds. We will now use the results from our mixture to determine calibration factors (relative response factors) for the detector, and then use these for the analysis of a commercial tablet. 

When the critical value is exceeded, y > yc, then the analyte under examination is proved to be present in the sample. A quantification of the critical value by means of a calibration factor S = b or function y = a + fix is not very meaningful, but when it is done notwithstanding, then two consequences must be taken into account ... 

After the end of the 4-day exposure, the detectors were returned to EML for analysis. The amount of radon adsorbed on the carbon device was determined by counting the gamma rays of radon progeny in equilibrium with radon. The concentrations of radon in the buildings were determined from the radioactivity in the device and the calibration factor, obtained in a radon chamber, that takes into consideration the length of exposure and a correction for the amount of water vapor adsorbed during the exposure. The lower limit of detection with this technique is 0.2 pCi/1 for a measurement period of 4 days when the test sample is counted for 10 min, 4 days after the end of exposure. More than 90% of the radon monitoring devices were analyzed successfully. Most of the unsuccessful measurements were due to delays or losses caused by the participants. 

The calibration of this method was performed with Rn-222 and Rn-220 emanating from standard Ra-226 and Th-228 solutions, respectively. It is defined that the calibration factor is the ratio of experimental counts to one expected from used radon and/or thoron gases by using Equation (7) The calibration factors of radon and thoron were evaluated to be 0.81 and 0.31, respectively. 

The instrument was calibrated using a 1.5 liter flow-type ionization chamber The calibration factor was evaluated to be 0.318. 

A procedure which enables the response of an instrument to be related to the mass, volume or concentration of an analyte in a sample by first measuring the response from a sample of known composition or from a known amount of the analyte, i.e. standard. Often, a series of standards is used to prepare a calibration curve in which instrument response is plotted as a function of mass, volume or concentration of the analyte over a given range. If the plot is linear, a calibration factor... 

Although the response of the detector is usually proportional to the concentration of the test substance, this relationship can vary and it is essential that the response to a series of standard solutions is measured and a calibration factor or curve determined. 

In the infrared detection system, the sample is weighed into a special ceramic boat which is then placed into a combustion furnace at 1371°C (2500°F) in an oxygen atmosphere. Most of the sulfur present is converted to sulfur dioxide, which is then measured with an infrared detector after moisture and dust are removed by traps. The calibration factor is determined using standards approximating the material to be analyzed. 

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