Calibration checks

The next step is to show that the response for the analysis of any target compound is linear. This step is known as the initial calibration and is achieved by the analysis of standards for a series of specified concentrations to produce a five-point calibration curve (Figure 41.2a, b). On subsequent days, a continuing calibration must be performed on calibration check compounds to evaluate the calibration precision of the GC/MS system. 

Continuing calibration for a Series Method is performed using calibration check compounds. Surrogate compounds are added to the matrix before sample preparation to evaluate recovery levels. To check GC retention times, internal standards are added to a sample after its preparation for analysis. 

In general, it appears that the Micromerograph, provided that frequent calibration checks are performed, is a good, reproducible instrument for size measurement. The operator time involved is less than with most other methods, and the calcns are not complicated. As in all sedimentation methods, only when the sample particles are spherical does the Stokes diameter that is measured become a measure of absolute particle size. Microscopic examination should be used to check on particle shape and the effect of deagglomeration... 

Display Calibration Check Graph) The calibration points as obtained under (Accept) above remain as is, but a renewed measurement yes, i of these same samples as unknowns is simulated vertical lines indicate the CL(X) that would be determined for these X = fiyes, mean)- The variability so observed mimics the within-calibration repeatability. Use the button [New Check] to repeat the simulation. 

Display Calibration Check Table) Numerical results for the above item, including the back-calculated values in [% of nominal] format. 

Labelling and Calibration Check calibration certificate, indicate equipment identification details ... 

Insertion of the ambient temperatures in Eq. 1 results R0 in and a. Since the ambient temperature is calculated from a polynomial funtion (eq. 2) it is necessary to determine the polynomial coefficients by a least square fit regression over the ambient temperature range 0-50°C. Together with S0,. Si, b, and c, these values are written by the calibration computer to the non volatile memory of the microcontroller. As a calibration check two additional blackbody readings are performed at a third ambient temperature (see Fig. 3.48). 

Note This experiment assumes that a permanent log and a quality control chart are constantly maintained for each analytical balance in use in the laboratory. Each day you use a given analytical balance and log in with your name and date. The following calibration check should be performed weekly on all balances. If, according to the log, the calibration of the balance you want to use has not been checked in over a week, perform this procedure. Review Section 3.3 for basic information concerning the analytical balance. 

We are currently checking orifices prior to each survey with the direct reading rotameter, and washing them in isopropyl alcohol afterwards. Every six months, the calibration checks are performed with the wet test meter. As long as field checks and rotameter calibration checks agree with the bi-annual wet test meter calibration results, we feel the orifices are performing accurately. 

It has already been mentioned that control of a continuous process includes control and monitoring of raw materials used in the process. This is a very successful area of application for NIR because of the minimal sample preparation required, the robustness of the instrumentation and its ability to measure both chemical and physical properties [117]. Libraries of raw material can be compiled, which can then be shared between manufacturing locations given adequate calibration checks between measuring equipment [118]. 

Written records of such calibrations, checks, examinations, or inspections shall be maintained, as specified in 212.183. 

Calibrate, check, and document all critical process instrumentation. 

Check and document that the pumps conform to purchase specifications. Connect the pumps to the required utilities and document that the utilities are correct. Tighten flanges and mounts. Fill pumps with oil (if required). Check shock mountings and remove shipping restraints. Calibrate. Check and document all critical process instrumentation. 

Thermocouples calibration check report after test... 

Thermocouple calibration check report after test (SIP and temperature distribution study)... 

Printout for thermocouple calibration checks after study... 

When dealing with large numbers of samples and replicates, we perform periodic calibration checks to make sure that our instrument continues to work properly and the calibra-... 

Performance test samples (also called quality control samples or blind samples) are a quality control measure to help eliminate bias introduced by the analyst knowing the concentration of the calibration check sample. These samples of known composition are provided to the analyst as unknowns. Results are then compared with the known values, usually by a quality assurance manager. 

Together, raw data and results from calibration checks, spike recoveries, quality control samples, and blanks are used to gauge accuracy. Analytical performance on replicate samples and replicate portions of the same sample measures precision. Fortification also helps ensure that qualitative identification of analyte is correct. If you spike the unknown in Figure 0-5 with extra caffeine and the area of a chromatographic peak not thought to be caffeine increases, then you have misidentified the caffeine peak. 

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