Why do we Need to Calibrate Equipment
Calibration is the process of associating two measurements having in mind the equipment these measurements originate from use the same standard unit and therefore, the process intends to check for accuracy and precision. It should be known that one of the measurement equipment serves as the reference standard. Nonetheless, different countries use different standards, which also vary with the type of industry. As such, different manufacturers require their equipment to be calibrated after a certain period. This factor highly determines when an equipment should be calibrated other than other reasons to be stated later.
There are equipment that require a pre-calibration test which determines whether the equipment are fit for the calibration test whereas other equipment could just be submitted for the calibration test whether they are working properly or not. Generally, calibration involves adjusting the output or indication for the readings in the measurement instrument. Because the instrument is tested along a certain range of interest, it becomes possible to check if the instrument works as required. There are different ways of calibrating an instrument. For example, a digital thermometer is calibrated by a simulated temperature value. This means that a test instrument uses a voltage equivalent and a specific temperature on the digital thermometer. The results are recorded and the thermometer is considered calibrated.
Why and When to Calibrate
Regular frequency calibration ensures your equipment provides knowledge and evidence that is true and can be relied on as the correct value. According to the International Laboratory Accreditation Cooperation, calibration works to known the uncertainty in the measuring instrument, to identify any alteration of the measuring instrument, and to improve estimated deviation between the reflected value and the reference value.
How often you decide to calibrate your instrument is dependent on the way you balance risk and cost. Definitely, the more frequent your instruments are calibrated the lower the risk of providing questionable measurements. Besides, it is important to consider annual calibration especially for electrical instruments. Nonetheless, equipment used every day should have shorter calibration cycles as compared to instruments used once very month.
There are various certifications in relation to ISO that a calibration personnel or company should have if you are to send them your measurement instruments. However, these certifications vary from country to country though there is a possibility of using the same certificate in different countries if those countries have a common agreement in terms of the certificates they use to approve calibration officials. As such, always check for this certification to ensure your equipment does not move from bad to worse. This is equally important for the resources and time that might take the calibration to be done.
A good example of the best calibration practice from a company or calibration personnel is providing you with prove of certification way before you send them your equipment. Secondly, it is always good to do a background check on such individuals or company with the relevant authorities. Having a firm background with relevant authorities makes it easy for you to become loyal to a calibration provider. The accrediting organization is also in a position to provide you with links or connections to renowned and approved calibration companies in your country or region.
When planning for calibration, always consider the cost of the necessary correction. This is equally important as how reliable your instruments should be on the long run. Also, take into consideration the extent and severity of the problem, the trend data as obtained from previous calibration schedules, and how often the problem seems to wear and drift off. There is also the aspect of environmental conditions, personnel use and transportation. Equipment that is affected by climatic conditions, use vibration or ionizing radiation processes require a special calibration. Always consider arranging for special transportation of equipment, and how your personnel use the equipment determines their calibration cycle.
You should know that as equipment age, they also undergo changes in mechanical stress and temperature. As such, you should put up counter measures to ensure their critical performance is intact even as the equipment tends to degrade gradually. This ensures that the test results remain reliable and the design as well as production quality can be depended on. One thing about equipment is that inaccuracy and lack of precision always comes and cannot be avoided. As such, it is always good to plan and budget for calibration.
Always keep your previous calibration schedules and results in good record to ensure that you can follow up on how your equipment is aging or rather, how fast the “drift” is taking place. This allows you to make early arrangements for the replacement of old equipment or calibration. Beware of traceable calibration services. There are companies and personnel that offer this kind of calibration in the place of accredited calibration. Most accreditation authorities do not explicitly approve traceable calibration services.