Specific resistance (at 20 ° C)

Are you interested in the resistivity of alloys at room temperature from the company-supplier AvecGlob? Here you will find interesting information on this topic.

Factors affecting the value of the resistivity

Resistance depends on a number of factors, including surface cleanliness, humidity, temperature, applied voltage or applied current. Indications of temperature and relative humidity are an integral part of the test. Some instruments have auto-tuning and can operate at low power levels, and at very low and sensitive resistivity measurements. Resistance can not be measured directly on any meter; this is the calculated value obtained by dividing the applied voltage by the current through the conductor. In a typical ohmmeter or multimeter, small currents are used, after which the voltage is measured and the resistance in Ohms (Ohm) is displayed.

Applied measurement technique

Numerous instruments can measure resistance, either in combination with another instrument, or separately. The accuracy and sensitivity depend on the test conditions, sample rate and resolution of the scale / display.

Very low and very high resistance values are usually measured by different types of counters and probes. Measurements with high resistivity are usually achieved using either a megohmmeter or an insulation resistance meter (insulation resistance). Very low resistance values are measured by several different instrument combinations, and in some cases by very precise specialized instruments.

To measure the resistance or resistivity, two or four wires are required. Measuring the resistance with two wires is the simplest and most accurate for many applications. A portable multimeter is used for measurements. The multimeter applies a very small DC current to the unknown resistance and measures the voltage drop across the resistance, displaying the results in Ohm. The inputs and contacts have some resistance, which is included in the result.

Supplier — the company AvecGlob — offers at affordable prices from the manufacturer of various metals and alloys. The supplier guarantees the timely delivery of products to any address specified by the consumer.

Measuring circuits

For better accuracy with two-wire tuning, a laboratory multimeter can measure the resistance of leads and contacts in a circuit with a remote sample.

The meter can then reset this value to zero when measuring the sample to obtain the actual sample value.

In a four-wire measurement, the source current is separated from the test leads, thereby eliminating the effect of wire resistance on the measurement. Four-wire

Resistance measurement is the most accurate way of measuring very small resistances. Current and voltage are used in two separate circuits, also called sources and chains of perception. This is called the Kelvin bridge, and Kelvin clamps are used to fix the sample. Given the known current from the source, the counter can then calculate and display the resistance.

Examples of resistivity of some metals and alloys at 20 ° C

Supplier — AvekGlob company — offers to purchase various metals and alloys by any number of nomenclature profiles. Products can be bought at a price formed on the basis of European and world standards of production. Implementation is possible in bulk and retail, for regular customers, a flexible system of discounts operates.