NDZK-IV Vacuum Degree Tester for Vacuum Switches

Product Introduction

       According to JB8738—1998 "Vacuum Interrupters for 3.6—40.5KV AC High-Voltage Switches" formulated by the "National High-Voltage Switchgear Standardization Technical Committee," "Internal Gas Pressure Measurement and Permissible Storage Period Inspection" is a mandatory test item for units producing and using vacuum interrupters in high-voltage switchgear. It stipulates that the permissible storage period for interrupters is 20 years. The internal gas pressure of the vacuum interrupter should be lower than 6.6×10⁻² Pa.

       Vacuum interrupter permissible storage period inspection method: Use a pulsed magnetic vacuum degree tester to measure the internal gas pressure of the vacuum interrupter and record the measured value P1 (Pa). After letting it stand for a period of time t (d), use the same instrument to measure its internal gas pressure again and record the measured value P2 (Pa). The standing time t should not be less than 7 days. Calculate the permissible storage period T (years) using the following formula: T = (6.6×10⁻²) / (P2 - P1) × t / 365 (years).

       NDZK-Ⅳ Vacuum Switch Vacuum Degree Tester is a new-generation product developed by our company based on user feedback from the NDZK-Ⅲ model. It features higher testing accuracy, better stability, and a higher level of intelligence.

Product Features

       The common method for determining whether the vacuum degree of a vacuum tube has deteriorated is the power frequency withstand voltage method. However, this method can only identify interrupters with severely deteriorated vacuum degrees. When the vacuum degree deteriorates to 10⁻²–10⁻¹ Pa, although the breakdown voltage does not decrease, the interrupter is already unqualified. The NDZK-IV Vacuum Switch Vacuum Degree Tester uses a new excitation coil and applies the magnetron discharge method to test the vacuum degree of the interrupter without disassembling it. Simultaneously, it employs a microcomputer for synchronous control and data acquisition processing, achieving an on-site testing sensitivity of 10⁻⁵ Pa for interrupter vacuum degrees.

       The standout feature of this instrument is its use of a new excitation coil and data processing method, enabling non-disassembly measurement of vacuum degrees. It offers the advantages of ease of use, simple operation, non-disassembly measurement, and high testing accuracy. It is a practical testing instrument widely applicable to sectors using vacuum switches, such as power, steel, petrochemical, textile, coal, and railway industries.

Technical Parameters

☆ Test Object: Various models of vacuum switch tubes.

☆ Testing Method: Uses a new excitation coil for non-disassembly measurement of vacuum tubes.

☆ Applicable Range: This instrument is a multi-purpose device capable of testing various models of vacuum switches.

☆ Testing Range: 10⁻⁵–10⁻¹ Pa 

☆ Measurement Accuracy: 10⁻⁵–10⁻⁴ Pa,   15% 

      10⁻⁴–10⁻³ Pa,   15%

      10⁻³–10⁻² Pa,   10%

      10⁻²–10⁻¹ Pa,   10%

☆ Magnetic Field Voltage: 1700V

☆ Pulsed Electric Field High Voltage: 30KV

☆ Switch Tube Gap During Vacuum Degree Testing: Normal operating gap.

☆ Operating Environment: -20℃ to 40℃

☆ Main Unit Weight: 12kg

☆ Dimensions: 420×320×280(mm)

☆ Sampler: Magnetron coil