subject: The Role Of Process Calibration Instruments
[print this page] Processing calibration instruments refers to the comparison between measurements according to a known set of specifications. A separate device is used in order to measure the amount of variation the unit has from the said specifications. When the unit is found to be off, it is corrected according to the technical specifications.
The device generally is referred to as the standard, due to it having the assigned or known correctness. The unit that is being tested is referred to as the test instrument (TI), unit under test (UUT), or may be referred to by a different name according to the device being calibrated.
Originally, many of the measuring devices were easy to validate and intuitive. The first reference to the term of calibration is believed to have an association with the precise division that uses are dividing engine for the angles and linear distance. As for the measurement of the gravitational mass, this is usually obtained through the use of a scale.
Along with the introduction of the industrial revolution came the wide use of the scale for indirect measurements. One of the early examples of indirect measurements and its addition to existing direct measurement was the measurement of pressure. Prior to the industrial revolution, the most common type of pressure measurement device that was used was the hydrostatic manometer. However, this type of meter was not practical way to measure high pressure.
The Fundamental Calibration Process
Calibration starts along with the measuring instrument, which has the need to be calibrated. In order for calibration to occur, the instrument needing the calibration has to have the capacity to hold a calibration. This must occur through the calibration interval.
Therefore, the instruments design needs to be within engineering tolerance in order to obtain measurements. This especially applies when the instrument is used over a reasonable amount of time within its environmental conditions. When these things are present, then the instrument is more likely to attain optimal calibration of the instrument and in effect causing it to perform at its best.
When referring to the assigned tolerance values, these vary according to the industry type and country. In general, the manufacturer usually assigns the measurement tolerance. In addition, they tend to specify the storage and environmental range of use, while suggesting a calibration interval.
Often, the organization using the processing calibration instruments will assign the actual calibration interval according to the equipment's amount of usage. One of the most common intervals within the United States is six months. The way this is determined is according to the instrument being used for 8-12 hours a day, for a total of five days a week.
In the case that the instrument was used on the basis of 24 hours a day and seven days a week, this interval would be shorter. In order for the processing calibration instruments to be successful, calibration needs to be systematic and consistent in its use. Additionally, regular calibration needs to take in account any observations that are unexpected. Therefore, they may require further investigation beyond what the processing calibration instruments present.
