A slider includes a Tunneling Magneto-Resistive (TuMR) read sensor and a shunt resistor connected in parallel. The shunt resistor may be located in a read structure of the slider. The shunt resistor may reduce a total resistance of the read structure and any corresponding impedance mismatch between the read structure, a transmission line, and a preamplifier. The shunt resistor may be made of a material having a near zero thermal coefficient of resistivity (TCR) to test a quality of the TuMR read sensor. The TuMR read sensor may be deemed defective if its TCR deviates from a population average by a specific criterion. The TuMR read sensor may include a MgO tunneling barrier to improve signal strength. The TuMR read sensor may include a free layer that is able to be saturated with a perpendicular background field to calculate a more accurate TCR of the TuMR read sensor.