Role of Metrology

Introduction
The purpose of this page is to highlight the significance of metrology and to discuss topics of importance in metrology that have a significant impact on Trinidad and Tobago. We hope to present information our readers that will increase their understanding of measurement and how it may affect their lives. Our main objective is to influence the national community to recognise measurement and by extension metrology as a beneficial activity that, once properly utilised can solve many existing problems and can provide the basis of the solution of many others.

Metrology is defined as the science of measurement. In reality it is much more meaningful and important to modern life than that definition would suggest. In the past the main reflection of metrology activity in society was weights and measures, the inspection of measurement devices used in day to day trade.

Metrology is important to every area that has measurement of a value or quantity as part of its make up. For example the major industries in Trinidad and Tobago are the production of oil and natural gas. The volume of both these fluids produced and exported must be measured for taxation and royalty purposes. The measurement of gas quantities also requires the determination of pressures and both require the measurement of temperature. The accuracy of all of these will determine the efficiency with which our revenues will be accrued.

Why Metrology?
Our first topic is: Why Metrology? The answer is that metrology is there to ensure that measurements work. Measurement is part of the real world. It is performed with manmade instruments primarily by humans. It is not perfect and shares the limitations of other human activities.

The bulk of the application of metrology is to quantify and reduce the effect of this imperfection and finding new measurement methods that can reliably match the development of technology.

The Flaws
Measuring instruments all have a flaw, some intrinsic limitation that does not allow for the results it gives to be the absolute truth. The method and science of the measurement along with the design and construction of the instrument, even the way in which the measurement is defined can all contribute to the limit of correctness of a measurement. A ruler cannot measure a length shorter than the thickness of its lines and values between the lines must be visually estimated these are both limitations on its use.

Degradation
Manmade objects are always subject to natural degradation and to deterioration through wear and tear from use. Measuring instruments are no different and the results that they give tend to be less reliable with the passage of time. A ruler with worn out lines is useless and a crooked edge is a sure cause of error.

Variation
Variation is another phenomenon that acts against the correctness of measurements. Along with the factors mentioned above there are several natural and technological factors that can influence the outcome of a measurement. Variation is common in many activities of life and has given rise to terms such as ”luck” and “chance” . Metrology seeks to minimise variation in measurement to the point where it is not significant in the measurement. If this cannot be done then it is estimated and considered in the result. Old joiners and metal workers have a system of doing a measurement at least twice before cutting. No significant variation in the result is the signal to proceed to cut.

Ambient Conditions
The conditions existing at the time of a measurement can influence its outcome. The temperature, lighting conditions and the quality of the electricity supply are possible influence quantities in the value of a measurement.

Human Error
The limitation of human perfection is a reality that impacts on the reliability of measurements. Despite training and carefully written procedures conscientiously applied the effects of human error can only be minimised.

With the best of intentions metrology is needed to ensure that measurements can be trusted. Metrology can even be applied in some situations where intentions are not the best to give acceptable results.