ohmmeter, which may be one function of a multimeter. Usually, probes on the ends of test leads connect to the resistor. A simple ohmmeter may apply a voltage from a battery across the unknown resistor (with an internal resistor of a known value in series) producing a current which drives a meter movement. The current, in accordance with Ohm's law, is inversely proportional to the sum of the internal resistance and the resistor being tested, resulting in an analog meter scale which is very non-linear, calibrated from infinity to 0 ohms. A digital multimeter, using active electronics, may instead pass a specified current through the test resistance. The voltage generated across the test resistance in that case is linearly proportional to its resistance, which is measured and displayed. In either case the low-resistance ranges of the meter pass much more current through the test leads than do high-resistance ranges. This allows for the voltages present to be at reasonable levels (generally below 10 volts) but still measurable. Measuring low-value resistors, such as fractional-ohm resistors, with acceptable accuracy requires four-terminal connections. One pair of terminals applies a known, calibrated current to the resistor, while the other pair senses the voltage drop across the resistor. Some laboratory quality ohmmeters, milliohmmeters, and even some of the better digital multimeters sense using four input terminals for this purpose, which may be used with special test leads called Kelvin clips. Each of the two clips has a pair of jaws insulated from each other. One side of each clip applies the measuring current, while the other connections are only to sense the voltage drop. The resistance is again calculated using Ohm's Law as the measured voltage divided by the applied current. Standards Production resistors Resistor characteristics are quantified and reported using various national standards. In the US, MIL-STD-202 contains the relevant test methods to which other standards refer. There are various standards specifying properties of resistors for use in equipment: IEC 60062 (IEC 62) / DIN 40825 / BS 1852 / IS 8186 / JIS C 5062 etc. (Resistor color code, RKM code, date code) EIA RS-279 / DIN 41429 (Resistor color code) IEC 60063 (IEC 63) / JIS C 5063 (Standard E series values) MIL-PRF-26 MIL-PRF-39007 (Fixed power, established reliability) MIL-PRF-55342 (Surface-mount thick and thin film) MIL-PRF-914 MIL-R-11 Standard Canceled MIL-R-39017 (Fixed, General Purpose, Established Reliability) MIL-PRF-32159 (zero ohm jumpers) UL 1412 (fusing and