Abstract
A set of seven single junction thermal converter Micropotentiometers (μPots) has been constructed at the National Institute for Standards (NIS), Egypt. This set has been built to cover the low ac voltage ranges from 2 mV to 200 mV at frequencies from 40 Hz up to 20 kHz. The construction of the μPots set has been presented and an adopted calibration method has been performed as well. This method has been performed by means of a step-down procedure using a Digital Multi-Meter (DMM). The scaling procedures have been carried out in sequential steps starting from the calibration of the 200 mV-μpot by using DMM that is accurately calibrated at its 200 mV ac voltage range down to 2 mV-μPot. Furthermore, a new automatic calibration system has been established to achieve the scaling procedures. This system has been specially designed using Laboratory Virtual Instrument Engineering Workbench (LabVIEW) software to overcome the deficiencies of manual methods. The automatic calibration has been investigated of all mPots at different frequencies. The ac-dc differences for the μPots and their uncertainty evaluation from 2 mV to 200 mV at different frequencies from 40 Hz to 20 kHz have been determined.
Highlights
The electrical SI units are defined and realized as dc electrical quantities. ac electrical quantities can’t be directly determined in terms of SI units, so ac quantities have been determined in terms of the dc quantities
There are different types of μPots according to the thermal converter used in its construction such as single junction thermal converter (SJTC) and thin film multi junction thermal converter (MJTC)
MJTC in planar technique are used for voltages down to 100 mV [5] and integrated μPots are designed in the same thin film technology [4], SJTC are widely used for ac-dc transfer because of their simple construction and ready availability [6]
Summary
The electrical SI units are defined and realized as dc electrical quantities. ac electrical quantities can’t be directly determined in terms of SI units, so ac quantities have been determined in terms of the dc quantities. A device fulfilling this need is called radio frequency μPot. The μ pot is a very precision standard for determining a low output ac voltage over a wide range of frequencies. MJTC in planar technique are used for voltages down to 100 mV [5] and integrated μPots are designed in the same thin film technology [4], SJTC are widely used for ac-dc transfer because of their simple construction and ready availability [6]. This paper is dealing with a construction as well as an adopted automatic calibration method of a precise SJTC μPots set. This μPots set is implemented as a part of upgrading the ac capabilities at NIS. The calibration results of all the μPots and their associated uncertainties are fully investigated as well
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
