The main purpose of this paper is to study the uncertainty budget of hydrometers calibration and the error of Cuckow’s method according the Signal-to-Noise Ratio Taguchi approach in order to analyse this two different kinds of methodology. The calibration of density hydrometers is influenced by some parameters; in order to research the influence of these factors in the measuring value, an experimental design with dynamic characteristics was applied. With this methodology, five control factors were considered, at two levels each and a L32 Orthogonal Array was defined. It was evaluated the influence of each parameter (factor) and the interaction between them according Cuckow’s method and Taguchi methodologies. The simultaneous analysis of the error and the sensitivity leads to a proper choice of significant control factors and respective best levels in order to reduce the variability of the measurement system.

Mechanical forces can be sensed over a very broad input range (10 nN up to 100 kN) with high resolution and linearity by applying the photo-elastic effect in small solid-state lasers (diode-pumped Nd:YAG crystals). The input force vector modulates the optical frequency of the laser crystal. In our experiments sinusoidal, pulse, and transient forces are generated by a PCT drive in a special dynamic test set up. By simple autodyne detection of the laser beam and concurrent signal processing of the electrical beat signal, we can measure sinusoidal forces from DC up to 100 kHz modulation frequency. Frequency counter measurement of pulse forces can be performed within few microseconds. By digital filtering, the final value of structure-induced transient forces can be predicted with high precision in milliseconds.

This paper describes the metrological requirements and the measurements methods for calibrating nonautomatic weighing instruments. It also may be a useful guideline for operators working in calibration laboratories accredited in various fields. This paper is also intended to enable metrology laboratories to prove a given expanded uncertainty using suitable procedures. Two examples of calibration methods are given: one for electronic weighing instruments and another for the mechanical instruments. The described methods include information regarding the measurements standards used for calibration, environmental conditions, calibration procedures and estimation of the measurement uncertainty.

The present contribution examines how metrological specifications can be derived for a given type of torque transducer when specifications for use in the full nominal measuring range are known, but the specifications for use in a partial load range are required. metrological properties of a transducer in a partial load range can be estimated from data taken from specifications or calibrations in the nominal load range.

A torque comparison was carried out between the Centro Nacional de Metrología, CENAM (in Mexico) and the Instituto Nacional de Metrologia, Normalização e Qualidade Industrial, INMETRO (in Brazil), in order to estimate the level of agreement for the realization of the quantity and the uncertainty associated to its measurement. The comparison was carried out in a range starting at 20 N·m and up to 100 N·m. The results obtained, deviations graphs (including the uncertainty for each torque applied of each laboratory) and the normalized error equation application results are presented in this document. This constitutes the first torque comparison within the Sistema Interamericano de Metrologia (Interamerican Metrology System, SIM) and has the classification number SIM.7.27 BK.