Permanent monitoring
In order to prevent system errors in switchgear and thus network outages, the permanent monitoring of the gas density is essential.
The model GD-20 calculates the current gas density from the pressure and temperature using a complex virial equation in the gas density sensor´s powerful microprocessor. Changes in pressure resulting from thermal effects will be compensated by this and will not affect the output value.
Modbus® fieldbus
The RS-485 interface communicates using the Modbus® RTU protocol. The instrument's output parameters and their units can be configured and read according to requirements.The GD-20 model can be freely configured ex-works for any defined gas mixture consisting of SF6, N2, CF4, O2, CO2, C4-FN, He and Ar.
The calculation is based on the partial pressure method of the individual gas components.
Signal stability
Due to its high long-term stability, the sensor is maintenance-free and requires no calibration. Due to the hermetically sealed weld seam and a measuring cell design without sealing elements, the permanent leak tightness of the measuring cell is ensured.
The gas density sensor is also available with analogue output signal (4 … 20 mA) for output of the compensated pressure (p at 20 °C [68 °F]) or SF6 gas density in g/l.
