Calibration procedure and uncertainty analysis of an electronic scale based on two-current source supplied circuit

Abstract

Original scientific paper The article presents the prototype version of an original weight scale in which a non-conventional supplying circuit of strain gauge load cells is applied. The paper discusses construction of an electrical circuit, the way of strain gauge transducer connection and the measuring procedure. As far as the authors know, this novel electrical circuit and its application in a weight scale system have never been mentioned in literature. The specifications for directreading weight scales typically include readability, repeatability, linearity and eccentricity. The values of these parameters were estimated and used for calculation of the weight measurement uncertainty in the tested measuring range of the designed device. Keywords: measurement uncertainty; strain measurement; weight measurement Postupak baždarenja i analiza nesigurnosti elektronske vage na temelju strujnog kruga istosmjerne i izmjenične strujeIzvorni znanstveni članak Rad predstavlja verziju prototipa originalne vage u kojoj je primijenjeno neuobičajeno napajanje ćelija tenziometra. U radu se razmatra konstrukcija električnog strujnog kruga, način povezivanja pretvarača tenziometra i postupak mjerenja. Koliko je autorima poznato, taj novi električni krug i njegova primjena na sustav vage nisu do sada spomenuti u literaturi. Specifikacije za vage s direktnim očitavanjem tipično uključuju čitljivost, ponovljivost, linearnost i ekscentričnost. Procijenjene su vrijednosti tih parametara i primijenjene u proračunu nesigurnosti mjerenja težine u ispitivanom rasponu mjerenja konstruiranog uređaja.

Levels and Patterns of Physical Activity and Sedentary Behaviour of Primary School Learners in Lagos State, Nigeria

“…Bodyweight was measured to the nearest 0.1 kg. The weighing scale was calibrated using repeatability and eccentricity tests before each week’s body weight assessment [ 33 ].…”