Class of accuracy in electrical measurements and voltmeters have a high but not infinite internal impedance. Thus the measured parameters are somewhat altered during the measurements. Let E be the EMF of the source R be the resistance of the load and r be the resistance of the ammeter. The current through the load is I When the ammeter is connected in series with the load the current I is The difference introduced by the measuring device is then, The ratio of the difference to the actual value is Class of accuracy in electrical measurements In electrical engineering class of accuracy is a figure which represents
Electrical impedance myography Electrical impedance myography Electrical impedance myography, or EIM, is a non-invasive technique for the assessment of muscle health that is based on the measurement of the electrical impedance characteristics of individual muscles or groups of muscles. The technique has been used for the purpose of evaluating neuromuscular diseases both for their diagnosis and for their ongoing assessment of progression or with therapeutic intervention. Muscle composition and microscopic structure change with disease, and EIM measures alterations in impedance that occur as a result of disease pathology. EIM has been specifically recognized for its potential as an ALS biomarker (also known as