Calibration and verification of weighing scales installed in hospitals and healthcare centres is indispensable to ensure its performance accuracy. A study was conducted to ascertain the performance of weighing scales in Ilala, Kinondoni, and Temeke hospitals located in Dar es Salaam region. The study administered fifty questionnaires to gather data from individuals working in these hospitals and healthcare centres as well as performing actual test of the installed scales. During the actual test, it was found that 38% of the scales delivered correct results, 48% were partially correct and 14% were incorrect. It was also found that 18% of tested scales were verified and stamped while 82% were neither stamped nor verified. Furthermore, the findings from the respondents show that 80% of the scales have not been repaired since they were purchased, 2% were repaired only once a year, while 18% were repaired at least once a year. It is concluded that the overall performance of the hospitals’ weighing scales was notsatisfactory. This is because only 38% of the scales delivered correct results while 62% delivered uncertain results. It is recommended that hospitals and healthcare centres should purchase weighing scales from the approved supplier by the Weight and Measures Agency (WMA) as this will minimize the poor performance of the scales used. It is also recommended that the Weight and Measures Agency (WMA) should establish a regulation that subjects the scales to metrological inspection and control, as well as raising awareness of the users of the scales on their proper use and storage

Introduction. Previous works considered the frequency characteristics and methods for fixing sensitive elements in the form of a wave ring resonator on surface acoustic waves in a housing made of various materials, as well as the influence of external factors on sensitive elements. It was found that the passband in such a case is sufficiently wide, which can affect adversely signal detection when measuring acceleration using the sensitive element under development. Therefore, it has become relevant to reduce the sensitive element’s bandwidth by changing the design of the interdigitated transducer (IDT).Aim. To demonstrate an optimal topology for an IDT with a low bandwidth, leading to improved signal detection when acceleration affects the sensitive element.Materials and methods. The finite element method and mathematical processing in AutoCAD and in COMSOL Multiphysics.Results. Nine topologies of IDT are proposed. All these types were investigated using the COMSOL Multiphysics software on lithium niobate substrates, which material acts as a sensitive element. The frequency characteristics are presented. The data obtained allowed an optimal design of the ring resonator to be proposed: an IDT with rectangular pins without selective withdrawal.Conclusion. Self-generation in a ring resonator can be performed by withdrawing no more than one pair of IDTs for 10 or more periods. In this case, the withdrawal of IDTs should be uniform. With an increase in the number of IDT withdrawals, the geometry of the ring resonator is violated, and the wave leaves the structure. The presence of a shared bus keeps the surface acoustic wave inside the IDT structure, and the narrowing of the periods towards the inner part of the structure makes it possible to improve the frequency characteristics of the ring resonator on surface acoustic waves.