Methods for the calibration of the gain of a digital lock-in amplifier in the low frequency (<100 Hz) range and for voltage range between 1 and 100 µV are investigated.
The measurements aim to the mutual validation of the different methods with a travelling standard.
Final Report 2021-01-18
The EURAMET TC-EM Project 1466 “Calibration of lock-in amplifiers” concerned the mutual validation of the performance of the two new setups respectively developed at METAS and INRIM.
These new setups for the calibration of lock-in amplifiers in the low frequency range (below 1kHz) allow to determine the lock-in magnitude error with an uncertainty of the order of 1e-4 or better, that is, two orders of magnitude lower than the typical accuracy from factory specifications.
In February 2020 the INRIM setup was moved to METAS for on-site measurements. The results and discussion of the comparison have been published, along the description of the new INRIM setup, in A. Cultrera et al., “A new calibration setup for lock-in amplifiers in the low frequency range and its validation in a bilateral comparison”, Metrologia, 2021, https://doi.org/10.1088/1681-7575/abdae0.
The outcome of this project represents an advantage for many users interested in applications where lock-in amplifiers are employed as measurement instruments.
Progress Report 2020-02-26
The project partners investigated two different methods for the calibration of the gain of a digital lock-in amplifier. The INRIM calibration system was moved to METAS in the period 4 to 7 February 2020. The INRIM and METAS systems were employed to calibrate two lock-in amplifiers (Stanford Research SR850) on their 1 μV and 10 μV scales at two different frequencies (20 Hz and 103 Hz).
Data processing and final reporting is ongoing.