Calibration Test Benches

Make provision in plant premises to immediately attend and recalibrate faulty 

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As reported in Chap. 2, all aftertreatment devices have to be described mathematically with high accuracy. Therefore, aU chemical reactions and heat transfer phenomena are represented in a chemical and physical form. Since computational time has to be kept short, global reactions and rate formulations based on Lang-muir-Hinshelwood type are considered. Moreover, the calibration of the models represents a major step in the modeling work, requiring time and costs and directly affects the accuracy of the simulation of exhaust aftertreatment systems. For the development of control strategies, it is necessary to consider all affected aspects of the powertrain in form of a virtual test bench. The overall simulation tool includes the catalytic parts but also devices like sensors and ECU functions, which interact... 

Calibrating instrumentation with standard test equipment and making all required adjustments and control point settings. Bench calibration of instruments at jobsite (Owner witnessed and approved) prior to installation is acceptable. 

GLP Federal Register, December 1978 also see Williams and Hottendorf, 1997). These define technical matters such as laboratory methods, documentation, data handling, instrument calibration and much more connected with the actual conduct of toxicology testing at the bench level. 

The ability to configure certain parameters on-line is also useful, and certain instruments may be reranged remotely. Flowever, the ability to rerange and remotely calibrate instruments in the field is not as attractive as it may first appear. Accurate calibration often needs to be validated for the product and process to be viable, and usually this can be performed only on a bench test or during a plant shutdown. In addition, the question of security of access to changing parameters must also be validated. 

Calibration and response times should be verified by means of tests that do not necessitate the removal of detectors from their installed locations, unless such tests are not capable of determining whether changes in response time are beyond the acceptable limits. In such cases, sensors should be removed for a special bench test if this is practicable. If it is not practicable, then the manufacturer s test results may be used, provided that ... 

To evaluate the accuracy of the equipment under test, 8 bench trials applying accelerations with different amplitudes and directions were performed. Acceleration values obtained by the tested equipment were converted in RMS values to allow the comparison with readings performed by the calibrated accelerometer. Obtained data from devices and comparison are presented in the Table 3. 

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