!Under construction!

Lock-in measurement using virtual instruments

The widely spread lock-in technique allows very high sensitive measurements even the signal can be extracted from the magnitudes greater noise. The commercially available lock-in amplifiers are relatively expensive, so we have developed cost-effective, virtual instruments. In our work we have assemble some easy to build, open-source measurement system based on the lock-in technique and what we also use successfully in our academic education, research and development work.
We have also built a practice in the context of an Engineering Information Technology MSc course to measure the volume resistivity of different types of wires. The lock-in measurement implemented on NI hardware with supports of 4-wire measurement technique allows high precision measurement with 100 μΩ resistivity resolution.

The work had sent to the NIDays 2014 conference.

Hardware descriptions

Board top
The block diagram of the lock-in system.

Board bottom
Photo of the lock-in system implemented on NI_USB_6211.

Software download

Lock-in practice of the Engineering Information Technology MSc course