Research objectives and hypothesis/research questions:
The aim of this paper is to present partial results of an experimental study on the influence of measurement uncertainty on gauges used at different stages of product manufacture. The authors will answer the problem questions: - What effect does a change in the standard, a change in the operator performing the measurement and environmental conditions have on the measurement result? - How do the results of gauge measurements affect the perception of products? A research hypothesis was formulated: it is assumed that the conditions and method of performing metrological confirmations of gauges have an impact on the quality and safety of manufactured products.

Research methods:
In order to check the effect of selected measurement uncertainty magnitudes on the measurement result, a research experiment was conducted in which 10 jaw gauges were measured using: two gauges, two operators, and the measurement was performed at two different temperatures. In addition, the effect of temperature on gauge blocks (which is the main standard for jaw gauges) was compared using two gauge blocks: steel and ceramic with a nominal value of 100 [mm] with a grade K gauge block using a two-sensor comparator. An analysis of the gauge block check certificates (external and current) was also carried out, compiling the results of the center length error. The final element was the analysis of drawing assumptions for the ring thread gauge and M14x0.75-6h counter gauge, along with a comparison on real test objects.

Main results:
The study confirms the validity of using laboratory conditions when performing metrological confirmations of gauges, since, depending on the required tolerance and type of gauge, the sum of all measurement uncertainties can significantly affect its status and the acceptance of the product. Gauges are a type of standard, the measurement of which is often done by pressing – organoleptically. Depending on the operator, both the gauge and the product can be classified differently, hence the best solution would be to use modern electronic devices, where the measurement result is given automatically. In this way, the measurement is more reliable, both human error and system unreliability can be excluded.

Implications for theory and practice:
Estimating measurement uncertainty comes at an additional cost: increased personnel and other restrictions. However, as the experiments indicate, it is necessary for practical use. A broader treatment of this problem will be the subject of further research.