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I would like to know if it’s possible to measure SMD shunt resistors using resistometers and probes, especially without relying on solder pads. To achieve this, it’s essential to have predefined measuring distances for the contact points.
Additionally, how does the measurement process work when using a pad on a PCB? Why is it that every manufacturer can independently define their measurement points?
I believe the probes might cause an inaccurate reading of the resistance value. I haven’t worked with a resistometer but from what I was able to locate it may be best to use the Kelvin (4-wire) measurement technique to minimize the effects of contact resistance and measurement errors. Please read over this document on how to use the 4-wire Kelvin method https://www.digikey.com/Site/Global/Layouts/DownloadPdf.ashx?pdfUrl=B4DE7F3A5EC740549D2813C4F7636296
The question is not whether using such a measurement technique is “possible”, but whether or not it can be trusted to deliver results that are satisfactory for your specific purposes.
The difficulty with measuring low-value shunt resistors is that the resistance of the solder joints and mounting pads can be significant compared to the value of the resistor itself. As demonstrated in this resource simply changing the point on the kelvin-connected mounting pad can affect measurements by something on the order of ~1%.
Since shunt resistors come in a variety of shapes & sizes, it’s not practical to define one single measurement technique/pad layout that applies to all of them. By defining that variable for a given product/series, manufacturers can reduce or remove one source of error or disagreement.
The need for production testing would suggest that there are indeed techniques for measuring such devices without soldering them in place. The fixtures for doing so are going to be more sophisticated than two sets of cheap multimeter leads however.