WIKA data sheet SP 60.79 Applications ■ Medium and high-voltage equipment ■ Gas density monitoring in closed SF6 gas compartments ■ Remote monitoring of the SF6 condition ■ Raising an alarm when defined limit values have been reached ■ Ideally suited for smart grid or modernisation projects ■ Modbus® delivers measured values for pressure, temperature and gas density as digital signal ■ The 4 ... 20 mA version outputs the absolute pressure at 20 °C [68 °F] or the gas density in g/l as an analogue signal for SF6 gas ■ Compact design with only one process connection ■ Suitable for alternative gases Left: Hybrid gas density monitor with integrated transmitter, model GDM-100-T Right: Hybrid gas density monitor with attached transmitter, model GDM-100-T Gas density is a crucial operating parameter for high-voltage plants. If the required gas density is not present, safe operation of the plant cannot be guaranteed. The WIKA gas density measuring instruments provide reliable warnings against dangerously low gas levels, even under extreme ambient conditions. If the gas density drops as a result of a leakage, the switch contacts will switch. In addition to the traditional gas density monitor, with the model GDM-100-T high-precision sensors and evaluation electronics are incorporated. Via the on-site display, the pressure based on 20 °C [68 °F] can be read directly on the instrument. With the integrated switch contacts, simple switching tasks can be realised quickly and without complication. The integrated 4 ... 20 mA or Modbus® sensors integrated or attached to the instrument enable remote monitoring of the plant. WIKA data sheet SP 60.79 • 01/2022 The measured data for pressure, temperature and gas density are transmitted using the standardised Modbus® RTU protocol. The model GDM-100-T can also be configured for alternative gases consisting of N2, CF4, O2, CO2, 3M™, Novec™ 4710, He and Ar. The analogue version of the GDM-100-T uses the proven technology of the 4 ... 20 mA analogue signal and outputs the absolute pressure at 20 °C [68 °F] or the gas density in g/l for SF6 gas as an analogue signal. The data storage enables trend analysis to be carried out, so that critical SF6 gas conditions can be predicted and rectified in time. An optimisation of the maintenance strategy from time-based (TBM) to condition-based (CBM) is possible through the use of the gas density monitor. TBM =Time Based Maintenance CBM= Condition Based Maintenance ^ Part of your business Data sheets showing similar products: Hybrid gas density monitor with reference chamber with Modbus® or analogue 4 ... 20 mA output signal; model GDM-RC-100-T; see data sheet

■ ±2.5 % at ambient temperature -20 ... +60 °C [-4 ... +140 °F] and with calibration pressure in accordance with reference isochore (reference diagram KALI-Chemie AG, Hanover, prepared by Dr. Doring 1979) Vacuum and overpressure range with measuring span of 1.6 ... 16 bar [23 ... 232 psi] (at an ambient temperature of 20 °C [68 °F] and gaseous phase) G 1/2 B per EN 837, bottom stainless steel, spanner flats 22 mm Other connections on request. Stainless steel, welded Gas-tight: Leakage rate < 1 • 10-8 mbar • l / s Test method: Helium mass spectrometry Stainless steel Bimetal link (temperature...

All weld seams are qualified in accordance with DIN EN ISO 15613 in combination with DIN EN ISO 15614-1 and DIN EN ISO 15614-12 by the notified body TUV Sud. Tightening torque, test connection: 40 Nm ±10 % Gas-tight: Leakage rate < 1 • 10-8 mbar • l/s Digital sensor technology, model GD-20-D 1) Specifications apply to measurement of the compensated pressure over the entire temperature range from -40 ... +80 °C [-40 ... +176 °F], valid only for pure SFe gas. Accuracy is achieved after a maximum of 60 minutes operating time.

Suitable for the following gases Gas mixtures and components can be individually configured and combined ex-works. The calculation is based on the physical principle of the partial pressure method. The gas mixture cannot be changed subsequently. WIKA data sheet SP 60.79

Power consumption WIKA data sheet SP 60.79 • 01/2022

■ Circular connector M12 x 1 metal (5-pin) ■ Circular connector M12 x 1 plastic (5-pin) WIKA data sheet SP 60.79 • 0

For approvals and certificates, see website Model GDM-100-T with integrated transmitter and vertical process connection G 1/2 B, rotatable WIKA data sheet SP 60.79 • 01/2022

Model GDM-100-T with attached digital transmitter and vertical process connection G 1/2 B Model GDM-100-T with integrated transmitter and vertical process connection G 1/2 B with calibration valve WIKA data sheet SP 60.79 ∙ 01/2022

Model GDM-100-T with attached digital transmitter and vertical process connection G 1/2 B with calibration valve Model GDM-100-T with rear attached digital transmitter and vertical process connection G 1/2 B WIKA data sheet SP 60.79 ∙ 01/2022

Optional accessories Recalibration valve Model GLTC-CV Connection cable for Switching outputs ■ Enables easy recalibration of the gas density monitor without dismounting ■ Welded permanently to the instrument or available as loose valve for retrofitting Terminal without wiring Connector mounted on the instrument side, cable with loose ends WIKA data sheet SP 60.79 • 01/2022

Accessories for version with calibration valve Description Order number Protective cap for test connection (M26 x 1.5) Calibration system for SF₆ gas density measuring instruments, model BCS-10 See WIKA data sheet SP 60.08 Calibration system for SF₆ gas density measuring instruments, model ACS-10 See WIKA data sheet SP 60.15 Adapter from test connection (M26 x 1.5) to quick coupling Ordering information for mechanical instrument Model (with attached or integrated transmitter) / Process connection and connection location / Pressure unit at 20 °C [68 °F] / Filling pressure / Number of switch points...