Model 372 AC bridge and temperature controller
It’s been over a year since Lake Shore introduced the Model 372, the successor to our widely popular Model 370 AC resistance bridge. We are pleased to see the updated instrument find a home in many labs around the world. The Model 372’s matched-impedance (balanced) current source is just one of the features that continues to make this the instrument of choice for many applications—particularly those involving temperatures below 100 mK or resistance measurements at very low excitation levels.
The patented balanced circuit topology, when combined with the instrument’s other noise-reduction features, makes the Model 372 less sensitive to environmental noise than any other product of its kind. Because it is able to reject external sources of noise, extremely small excitation levels of just a few pico-amps may be used to perform accurate and precise temperature or sample measurements.
For more about the Model 372 and how its design addresses the dual problems of self-heating and measurement error caused by common-mode noise, be sure to read this application note. It goes into great detail explaining how Lake Shore’s patented matched-impedance current source topology differs from the single-ended (unbalanced) current source topology used traditionally in AC bridge designs.