Interlaboratory Comparison
Interlaboratory comparison is a testing programme in which multiple laboratories independently analyze the same reference sample so each one’s results can be checked against a known value, validating the laboratory’s accuracy, reliability, and the suitability of its analytical method.
Review of results of Interlaboratory test results
In today’s competitive environment it is not possible for any laboratory to exist in isolation. Your laboratory may have talented manpower in addition to top end test facilities but even then you cannot be absolutely sure that the results communicated will always be correct without any scope of doubt.
Interlaboratory comparisons serve the purpose of validating the capability of your laboratory to provide accurate and reliable results within permissible levels of uncertainty to your customers and also to ensure that the adopted analytical method is suitable for the intended purpose. All accredited laboratories are required to participate in inter laboratory testing programmes to uphold their technical competence and make their results acceptable to their customers.
Interlaboratory comparisons serve three basic objectives:
- Validation of a test method and establishment of the degree of uncertainty of results
- Establishing the suitability of the reference material used for the purpose
- Assessing the r reliability of test results obtained by the participating laboratories
The reference sample is selected and its analysis value is established but this value is not known to other participating laboratories. The sample is distributed amongst the participating laboratories and their independently reported test values are compared with the known value so as to establish the differences from known value and arrive at uncertainty limits.
Inter laboratory comparisons provide you an excellent opportunity to validate your laboratory performance and measurement processes. It reflects in totality a combination of practices adopted such as validity of the adopted procedure, quality systems, traceability of working standards and training competence of laboratory workers. It also helps to introspect your operations and take appropriate corrective actions from time to time.
Why is it important for a laboratory to participate in interlaboratory comparison programmes?
Interlaboratory comparisons validate a laboratory's capability to provide accurate and reliable results within permissible levels of uncertainty, and confirm that the analytical method adopted is suitable for its intended purpose. All accredited laboratories are required to take part in such programmes to uphold their technical competence and make their results acceptable to customers.
What are the three basic objectives of interlaboratory comparisons?
They validate a test method and establish the degree of uncertainty of results, establish the suitability of the reference material used, and assess the reliability of test results obtained by participating laboratories.
How does an interlaboratory comparison programme actually work?
A reference sample is selected and its analysis value is established, but that value is kept unknown to the participating laboratories. The sample is distributed, and each laboratory's independently reported results are compared against the known value to determine differences and establish uncertainty limits.
What does good performance in an interlaboratory comparison reflect about a laboratory?
It reflects a combination of practices including the validity of the adopted procedure, the strength of the quality system, traceability of working standards, and the training competence of laboratory workers.
What should a laboratory do with the results of an interlaboratory comparison?
The results provide an opportunity to introspect on operations and take appropriate corrective actions from time to time, rather than being treated as a one-off compliance exercise.
Is interlaboratory testing only relevant for accredited laboratories?
Accredited laboratories are specifically required to participate, but any laboratory operating in a competitive environment benefits from confirming that its results are accurate and reliable, since talented staff and good facilities alone do not guarantee correct results.