SF₆ Leak Meter

Leak Meter  Model LM 293                                                                    Price $5000/-

CSL LM 293 is a sensitive SF6 Leak meter that can measure SF6 Leak at PPM Levels. The unit is based on Electron Capture Detector combined with the state of the art electronics. This rugged unit is meant for shop floor or field operation.

Quick detection of leaks is achieved by mounting the detector and associated electronics in a hand held gun assembly, which is connected to the portable base unit through a long cable. This ensures a guaranteed response time of less than 3 seconds and provides a visual and audible alarm when the tracer gas is detected. 

Principle Of Operation

The SF₆ leak meter is based on detection by Electron Capture Detection (ECD) which responds only to electron capturing gases. The 300 mC Tritium is used as a radioactive source of low energy b -radiation and is kept inside the detector cell. The b – particles are all stopped with the detector cavity. When pure Argon or Nitrogen (carrier gas) passed through the detector, the b-particles ionizes the gas forming electrons and positive ions. Negative pulse of 1 micro sec. time duration and 6OV potential is applied to the detector electrode. The applied potential drive the electrons to the collector electrode where they are collected and measured as the standing current of the detector,. When an electron capturing gas such a SF₆ came into the detector on the argon stream, the SF₆ molecules will capture on electron. The negative ions formed always have a high probability of discharge on positive ions, thus reducing the electron current. In a new mode of operation the electron current is maintained constant .In this mode sensitivity is constant over a wide range of concentrations. The electron current is controlled in a closed loop control system which various the frequency of the polarizing supply to the detector and the electron current constant in clear Argon. The detector current ‘ld’ and the applied pulse frequency maintains the detector current equal to the reference current. When the electron capturing gas (sample) enters the detector, the detector current decreases, so producing an error. The voltage V subsequently developed indicates a change in the frequency by means of voltage to frequency converter, as this change is feedback so as to keep Id equal to Is. And mean while this error signal is amplified by the instrument and displayed in terms of PPM, which is matching with the concentration of the sample detected. 

Applications

Leak Detection From :

•   Switchgears

•   Gas Distribution systems

•  Accelerators

•  Electrical Equipments.

•  Study of Ventilation rates in buildings, rooms etc.

Specifications