Relative pressure transmitter GDHT-20

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Permanent monitoring of the relevant gas condition parameters in closed tanks For internal and external SF6-insulated equipment Special Features High-accuracy sensor technology Modbus® output protocol via RS-485 interface Ingress protection IP65 Very good long-term stability and EMC characteristics Compact dimensions Description The model GDHT-20 transmitter is a multi-sensor system with digital output for the measurands of pressure, temperature and humidity. Based on these measured values, the condition-related data can be determined. Permanent monitoring In order to prevent system failures in switchgear and, with that, network outages, the permanent monitoring of the gas density and moisture content is essential. The GDHT-20 transmitter calculates the current gas density from the pressure and temperature using a complex virial equation in the transmitter's powerful microprocessor. Changes in pressure resulting from thermal effects will be compensated by this and will not affect the output value. In addition, the GDHT-20 transmitter delivers humidity or dew point information, which enables monitoring within the terms of the Cigré directives and IEC standards. Modbus® field bus 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 GDHT-20 transmitter can be freely configured in percentage values by the user for any defined gas mixture consisting of SF6, N2, CF, O2, CO2, 3M™ Novec™ 4710, He and Ar. The calculation of gas density is based on the partial pressure method of the individual gas components.