Title :
Sources of normal mode offset in precision DMM’S
Author :
Moore, B. ; Early, M.D. ; Christian, L.A.
Author_Institution :
Meas. Stand. Lab. of New Zealand, Ind. Res. Ltd., Lower Hutt, New Zealand
Abstract :
We investigate the causes of the observed normal mode offsets in precision DMM´s. With a circuit simulation tool to model the front-end amplifier we have been able to qualitatively reproduce the observed offset in a commonly used 8.5 digit precision DMM. In general the cause of the offset is related to the symmetry of the front-end architecture. However it seems there are several mechanisms which contribute to the effect, and it is these that we are presently seeking to elucidate.
Keywords :
amplifiers; digital multimeters; circuit simulation tool; front-end amplifier; normal mode offset; precision DMM; Bandwidth; Bipolar transistors; Capacitance; Circuit simulation; Frequency; Impedance; Operational amplifiers; Preamplifiers; Protection; Resistors;
Conference_Titel :
Precision Electromagnetic Measurements Digest, 2008. CPEM 2008. Conference on
Conference_Location :
Broomfield, CO
Print_ISBN :
978-1-4244-2399-6
Electronic_ISBN :
978-1-4244-2400-9
DOI :
10.1109/CPEM.2008.4574970
