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Precision Shunt Resistor

USR UNR 4-3425 4020

Type	USR 4-3425	USR 4-4020	UNR 4-3425	UNR 4-4020
Resistance Range₁	0.05 to 650 Ohms			0.05 to 100 Ohms
Power Rating free air 70°C with heatsink	3W 30W	2.5W 30W	3W 50W	2.5W 50W
Thermal Resistance Rthj-c	3.5 K/W	3.6 K/W	2.1 K/W	2.2 K/W
Tolerances from 0.05 Ohms from 10.0 Ohms from 50.0 Ohms	0.1% / 0.25% / 0.5% / 1% 0.05% / 0.1% / 0.25% / 1% 0.01% / 0.02% / 0.05% / 0.1% / 0.25% / 0.5% / 1%
Stability	0.01%
Shelf Life Stability	25ppm / ΔR after 1 year 50ppm / ΔR after 3 year
Temperature Coefficient	max. ±5ppm/K (-55 to 155°C) typ. ±3ppm/K (-55 to 155°C) upon request ±1ppm/K (25°C to 60°C)
Voltage Proof	750 VDC
Thermal EMF	< 1 µV/°K
Operating Temperature Range	-55°C to 155°C
Resistor Material	NiCr-Foil
Substrate	Al₂O₃		AlN
Housing	Epoxy + Al-heatsink
Connector Material	Cu tinned
Max. Torque	1.0 Nm