The meter "Tangent 2000" is the noise-proof, highly-accurate and safe in service instrument designed for the control of the high-voltage equipment insulation parameters. The instrument identifying feature in regard to the other instruments of this application, commercially available in RF, is the crucially higher noise resistance provided by the existence of the testing voltage internal generator with the frequency that is different from the commercial. It allows obtaining the high accuracy of the measurements under the conditions of high level of noise disturbance on the open switchgears and finding out the minimal parametric variation of the insulation during the periodic inspection of the high-voltage equipment.