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Transmitter with Modbus Output - GDHT-20
Brand: WIKA Alexander Wiegand SE & Co. KGThe model GDHT-20 transmitter is a multi-sensor system with digital output for the measurement parameters of pressure, temperature and humidity. Based on these measured values, the condition-related data can be determined.
Features- High-accuracy sensor technology.
- MODBUS output protocol via RS-485 interface.
- Ingress protection IP 65.
- Very good long-term stability and EMC characteristics.
- Compact dimensions.
Specifications
Measuring Ranges
- Dew Point at ambient Pressure: -50° to +30° C
- Density: 0 ... 60 g/litre (8.87 bar abs. SF6 gas at 20° C)
- Temperature: -40° to +80° C
- Pressure at 20° C: 0 ... 8,87 bar abs. SF₆ Gas
- Pressure: 0 ...16 bar abs.
- Burst Pressure: 52 bar abs.
- Overload safety: up to 30 bar abs
- Pressure reference: Absolute
Accuracy
- Specifications only valid for Clean Gaseous SF6
- Dew Point: ± 3 K
- Density: ± 0.60 %, ± 0.35 g/litre (-40 ... 80° C)
- Temperature: ± 1 K
- Pressure: ± 0.20 %, ± 32 mbar (-40 ... < 0° C), ± 0.06 %, ± 10 mbar (0 ... 80° C)
Long-term Stability at Reference Conditions
- Temperature: ≤ ± 0.10 % of Span/Year
- Pressure: ≤ ± 0.05 % of Span/Year
- Dew Point: ≤ ± 0.50 % of Span/Year
Refresh Rate
- Density: 20 ms
- Temperature: 20 ms
- Pressure: 20 ms
- Dew Point: 2 s (Typical), auto-Adjustment cycle every 30 min.
Power Supply UB+
- DC 17 ... 30 V
Power Consumption
- Maximum 0.5 W (Maximum 3 W during the Heating phase of the humidity Sensor)
Electrical Connection
- Circular Connector M12 x 1 (5-Pin) Modbus RTU via RS-485 interface
Functionality Modbus
- Mixture ratio of SF6 to N2 or CF4 (Default 100 % SF6 gas) Customer-specific Sensor name
Measured Values with Alternative Units Can be Retrieved Directly in the Modbus Registers.
- Pressure: mbar, Pa, kPa, MPa, psi, N/cm², bar (At 20° C)
- Humidity: ppmv, ppmw
- Dew Point: °C
- Freezing Point: °C
- Relative Humidity: %
- Temperature: °C, °F, K
- Density: g/litre, kg/m³
Process Connections
- G 1 B, Male thread, Stainless Steel
- DN 20, Female thread
- G 1/2 B, Male thread
- Malmkvist
- G 3/8 JIS
- M10 x 0.5
- Via measuring chamber (see page 5)
- DN 8, Female thread
- Other Connections on Request
- Flange D40
Case
- Stainless Steel
Permissible Air Humidity
- ≤ 90 % Relative Humidity, Non-Condensing
Ingress Protection
- IP65, only when plugged in and using mating Connectors with the corresponding ingress Protection
Electrical Safety
- Protected Against Reverse Polarity, Protected Against Overvoltage
Dimensions
- Diameter: 48 mm
- Height: 96 mm
Weight
- Approximately 0.40 kg
- Permanent monitoring of the relevant gas condition parameters in closed tanks
- For indoor and outdoor SF[/size]6[size=3] gas-insulated equipment
