INSTRUMENTS WITH A DIGITAL SOUL

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AX-EL600W

Electronic load; LCD 4,3", with a backlit; 0÷150V; 0.001÷60A

AX-LCR42A

LCR meter; double LCD (19,999/1999), bargraph, with a backlit

AX-C708

Multimeter calibrator; V DC: 0,01m÷40m/400m/4/40/400V

AX-C605

Loop calibrator; V DC: 0÷28V; I DC: 0÷22mA; Current source: 0÷22mA

AX-DG1005AF

Generator: function; Band: ≤5MHz; LCD TFT 3,5"; Channels: 2

AX-DG1015AF

Generator: function; Band: ≤15MHz; LCD TFT 3,5"; Channels: 2

AX-LCR41A

LCR meter; LCD 5 digits; 3x/s; 0,0001÷9,999MΩ; R accuracy: ±0,3%

AX-C830

Thermocouple calibrator; V DC: -10m÷75mV; Measuring unit: °C, °F

AX-C850

RTD calibrator; R range: 0,01÷400/1500/3200Ω

AX-DG100-SOF

Software; Application: AX-DG105; Equipment: RS232 cable, software

AXIOMET Catalogue

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How to measure volume and surface resistivity of electrical insulation samples?

Volume and surface resistivity are two basic parameters of dielectrics.

Volume resistivity It relates to the current flowing inside insulation material under the action of an electrical field. It is always measured with the use of indirect method: volume resistivity is measured taking into account the effective area of measuring electrode and thickness of a sample. It is not easy to conduct measurements of this type due to the low flowing current. That is why while measuring volume resistivity of a given material, it is recommended to examine a lot of samples and average the results, especially when examined material is of variable structure.

Surface resistivity It relates to the current flowing on the surface of examined material. It is measured indirectly: surface resistivity is measured taking into account the effective length of measuring electrode and width of space between the electrodes. The measurement is not easy because the surrounding environment has influence on surface resistivity; this is clearly visible in case of materials having high resistivity.


It is recommended to measure volume resistivity with the use of three electrodes: measuring electrode and protective electrode on one side of dielectric, and voltage electrode on the other side. Measuring surface resistivity looks similar except that the electrodes are in different places: measuring and voltage electrodes are placed on the same side, whereas protective electrode is placed on the other side.