Calibration technician

Periodic calibration orders generated by the calibration program will contain information such as department, location, accuracy, data sheet number, SOP number, etc. needed by the calibration technician. Instrumentation in this program will include, but is not limited to, timers, monitoring probes (temperature, relative humidity, etc.), pressure gauges, balances, etc. 

Calibration Technician Accurate and repeatable measurements are essential to chemists working in research and industry. An instrument calibration technician adjusts, troubleshoots, maintains, and repairs the instruments used in laboratories and manufacturing plants. Their jobs require an understanding of the instrument s electronics and the use of computers and calibration software. For more information on chemistry careers, visit glencoe.com. 

The technician needs 11 minutes to prepare every sample solution and 13 minutes to prepare a calibration solution. A vial is filled in 1 minute. 

Building 6—An analyzer building, constructed of unreinforced masonry. A technician spends 2 hours a day in the building calibrating the equipment. 

Either before the dry run begins or while it is progressing, the instrument engineers and technicians should calibrate all the instruments over their full range and make certain they are connected to the correct recording and indicating equipment. 

It is important to remember that whatever volume measurement device is used, the analyst depends on it to deliver the indicated volume, i.e., it must be properly calibrated. Analytical chemists and technicians often depend on class A glassware to represent accurate calibration and hence do not usually feel the need for independent calibration. However, where non-class A glassware and alternative transfer devices are used, there is legitimate concern over their proper calibration. 

Traditionally, the education that chemists and chemistry laboratory technicians receive in colleges and universities does not prepare them adequately for some important aspects of the real world of work in their chosen field. Today s industrial laboratory analyst is deeply involved with such job issues as quality control, quality assurance, ISO 9000, standard operating procedures, calibration, standard reference materials, statistical control, control charts, proficiency testing, validation, system suitability, chain of custody, good laboratory practices, protocol, and audits. Yet, most of these terms are foreign to the college graduate and the new employee. 

Table 2-5 lists tolerances for micropipets from one manufacturer. As internal parts wear out, both precision and accuracy can decline by an order of magnitude. In a study17 of 54 micropipets in use at a biomedical lab, 12 were accurate and precise to <1%. Five of 54 had errors >10%. When 54 quality control technicians at four pharmaceutical companies used a properly functioning micropipet, 10 people were accurate and precise to <1%. Six were inaccurate by >10%. Micropipets require periodic calibration and maintenance (cleaning, seal replacement, and lubrication) and operators require certification.18... 

Calibration is time consuming when performed correctly. It may require 1 or 2 days to perform all the necessary steps (i.e., prepare stocks, filter, measure absorbance, check purity, dilute, mix, and inject calibrants). Once the stock solutions and mixed calibration solutions have been prepared, a calibration check can be performed in -4 hr. Sample preparation, depending on the matrix, may require a few minutes or a few hours. If an autosampler is unavailable for overnight injection the extracts are typically stable overnight, refrigerated at - 20° to 4°C. It is prudent to maintain the autosampler tray temperature from 4° to 15°C to reduce sample degradation. HPLC analysis of the extracted sample requires 20 to 60 min. Typically one technician can extract 12 to 24 samples per day to be analyzed overnight or the next day. 

A laboratory decided to test the energy content of peanut butter. A technician placed a 16.0 g sample of peanut butter in the steel bomb of a calorimeter, along with sufficient oxygen to burn the sample completely. She ignited the mixture and took heat measurements. The heat capacity of the calorimeter was calibrated at 8.28 kJ/°C. During the experiment, the temperature increased by 50.5°C. 

A lab technician places a 5.00 g food sample into a bomb calorimeter that is calibrated at 9.23 kJ/°C. The initial temperature of the calorimeter system is 21.0 ,C. After burning the food, the final temperature of the system is 32.0°C. What is the heat of combustion of the food in kj/g ... 

Closely related to preventive action is the process audit. Such an audit is performed as part of a laboratory assessment for each test on the proposed scope of accreditation. Performance of a test procedure is observed relative not only to the requirements of the ISO 17025 standard (or ISO Guide 25) but also with respect to performing the ASTM or ISO test method properly. As a minimum, the laboratory must have properly calibrated equipment, the current test method, and trained testing personnel. In addition, a representative number of test demonstrations will reveal whether good laboratory practices are observed in sample preparation, using the correct test parameters and calculating the results. When operators and technicians accept responsibility through such demonstrations, they tend to commit to the quality process. Real improvement occurs with involvement at all levels. 

Column entry fields for dates, times, and events (e.g., initial installation and calibration, updates, column changes, errors, repairs, performance tests, quality control checks, cleaning, and maintenance, plus fields for the name and signature of the technician making the entry). 

Advantages of using HPLC assays to measure saxitoxin include automated and continuous operation, increased sensitivity and increased precision. HPLC analysis of saxitoxin is limited in that it requires a skilled technician to operate the instmmentation, the analytical instmmentation is expensive, it requires extensive calibration and it is still not legally accepted for regulatory purposes. Advantages and limitations of LC-MS are similar to those... 

Figure 19 Example of a log-sheet for apparatus showing the entries for the regular maintenance and calibration activities the log-book or log-sheet has to be kept at the apparatus itself, since external technicians will have to provide records for their maintenance services, too, and the presence of the log-book will thus serve as a reminder.

However, one should not forget that the potentiometric mode has several drawbacks. The fabrication of most potentiometric tips is much more involved than that of the conventional amperometric tips. It is necessary to have the electrode made by a very skilled technician. Despite this, even when following a proven recipe the success rate is relatively low. The response of potentiometric tips is not always Nemstian and a calibration is required before and after performing the experiment. The behavior typically varies from one microelectrode to another. Potentiometric tips cannot rely on positive and negative feedback diffusion, thus it is difficult to assess the tip-substrate distance from the tip response. Several approaches are available, but most are cumbersome. In the potentiometric mode the response... 

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