Tracking force scale! One of these:
https://www.amazon.com/ExhilaraZ-Precision-Portable-Turntable-Tracking/dp/B07NNLBLP4/
Or if you want to be an analog badass ...
https://www.ebay.com/itm/255966765623

EDIT - I forgot the Shure only goes up to 3g, so not the best choice for your cart, where the recommended range goes up to 3.5g. Stick with the digital sucker.