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Time dependencies of the electrical resistance and electron density evolution in the discharge in a tube, with nitrogen at different pressures, with a diameter of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>9.2</mn><mspace width="0.166667em"></mspace><mi>mm</mi></mrow></semantics></math></inline-formula> and a length of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mspace width="0.166667em"></mspace><mi>cm</mi></mrow></semantics></math></inline-formula> were studied. A current pulse with an amplitude of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>500</mn><mspace width="0.166667em"></mspace><mi mathvariant="normal">A</mi></mrow></semantics></math></inline-formula> and duration of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mspace width="0.166667em"></mspace><mi mathvariant="sans-serif">μ</mi><mi mathvariant="normal">s</mi></mrow></semantics></math></inline-formula> has created the discharge in the tube. Instantaneous electron densities are estimated from the interference pattern in Mach–Zehnder interferometer using femtosecond Ti: sapphire laser beam. Laboratory results are compared with results of computer modelling by MHD computer codes NPINCH and ZSTAR. Time development of the discharge resistance according to experiment is measured and evaluated. Minimum measurable value of the electron density in the experiment is determined as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mrow><mn>2</mn><mo>×</mo><msup><mn>10</mn><mn>15</mn></msup></mrow><mspace width="0.166667em"></mspace><msup><mi>cm</mi><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></semantics></math></inline-formula>.