Trust is good. Measuring is better!
Designation: Universal main unit (all sensor types)


  • Monitor combustibles, O2, and a wide range of toxics
  • Monitor vaporized hydrogen peroxide (VHP) fumigation and disinfection
  • Plug and play smart sensors retain calibration and sensor data
  • Common platform (Main unit / Sensor / Pump) for all detection methods
  • Universal main unit (all sensor types)
  • Multifunctional sensor unit (New Intelligent sensor)
  • No internal tubing (main unit) / No coil (pump)
  • Front access, no tool required, easy sensor and pump replacement
  • Large size LCD screen
  • Various communication methods available (4-20mA, NT and PoE)
  • Minimal maintenance cost through enhanced troubleshooting firmware functions
  • Small mounting space
  • Environmentally friendly
  • Wide variety of sensors available


The new Model GD-70D smart gas detection transmitter series sets a new standard for performance, flexibility, and versatility. The GD-70D sample-draw transmitter offers an array of sensor technologies unmatched in the industry, including unique offerings, such as our hydrogen-specific or LEL versions.

The long life high capacity pump and wide variety of sensing elements are replaceable in a few seconds, with no tools required! The smart sensors retain all calibration and sensor-specific data in non-volatile memory, so sensors can be hot-swapped in the field with no programming required. The sensors also retain calibration information, which means they can be conveniently calibrated separate from the transmitter, avoiding transport of calibration gases to the field location. The GD-70D firmware automatically corrects for long-term zero and span “drift” minimizing maintenance and maximizing reliability.

Vaporized hydrogen peroxide gas detection (VHP) in fumigation disinfection of medical facilities, pharmaceutical environments, including cleanrooms, production filling lines, and chemical fogging for the food industry.

The GD-70D can be used as a stand-alone device, offering a number of communication protocols to existing PLC systems, or can be integrated with RKI’s Beacon series of single and multi-channel controllers.

All GD-70D transmitters include a large, easy to read integral LCD display, tri-color bar graph for visual notification of alarm status, programmable low and high alarm relays, and fault relay. Pump flow is self-tuning for maintenance-free operation. Because all GD-70D base units are identical, sensors can be interchanged with no programming or tools required, resulting in maximum flexibility to the user.



Model GD-70D GD-70D-NT GD-70D-ET
Communication 4-20mA DC DC power line communication PoE Method
Detection principle Different type depending upon sensor unit and detectable gas (see table)
Sampling method Sample drawing types (auto-adjustment of flow rate) 0.5 / min +/-10%
  • Large LCD display (white backlight)
  • Gas concentration
  • Flow rate, communication status, Pyrolyzer status, gas detected
  • Error code, content of error
Gas alarms Two alarm levels: 1st alarm – Red 2nd alarm – Red Fault alarm: Yellow
External output 1st, 2nd, and trouble alarms : Relay contact output for each alarm
Self diagnostic function System failure, sensor failure, flow failure, communication error NT / ET / Analog
Datalogging Event history, alarm history, calibration history. Alarm trend (180 sec before / after 1st alarm)
Operation temp. & humidity 0 ~ 40ºC, 30 ~ 70% RH (non-condensing)
Operating settings All operational settings are user adjustable through front panel
Power requirements DC 24V+/- 10%, approx 1.5W (Max 4W including sensor unit) Note: Approx. 2.5W (Max 5W) with SGU sensor unit PoE standard arrangement
Dimensions 2.8”W x 4.7”H x 5.9”D (70W x 120H x 150Dmm)
Weight Approx. 0.9kg (2.0lbs), including sensor unit
Mounting Wall-mounting base plate by 2 or 3 screws
Sampling tubing 4 x 6mm PTFE tubing recommended. Tube fittings provided as standard accessories
Bushing Cable type varies depending on communication method (Cable bushing optional)



Detection Principle Electro-chemical cell Semi-conductor Pyrolysis-particle Catalytic combustion
Gas detected and detection range Refer to list of detectable gases 0-2000ppm H2, CH4, or CH2F2 (R-32) in air and others 0-15ppm TEOS in air 0-100% LEL H2, CH4, and others
Self diagnosis function Sensor trouble, system failure
Date logging function Event history, alarm history, calibration history, Alarm trend (60 sec. before/after 1st alarm)



Model PLU-70
Application NF3 / TEOS gases detected in air
Usage Used by connecting to “GD-70D” (Main unit)
Power Lamp
  • LED (Green color)
  • Normal: Light-on
  • Warming-up: Flashing at every 1 sec interval
  • Trouble: Flashing at every 0.2 sec interval
Self-diagnostic function
  • Pyrolyser unit trouble
  • Fan trouble
  • System trouble
Operating temp. & humidity 0-40° C, 30-70% RH (non-condensing)
Operational settings All operational settings are user adjustable through front panel.
Power requirements DC 24V+/- 10%, approx. 25W (max)
Dimensions 2.8”W x 4.7”H x 5.9”D (70W x 120H x 150Dmm)
Weight Approx. 1.2kg (2.6lbs)
Mounting Wall-mounting base plate by 2 or 3 screws
Sampling 4x6mm PTFE tubing recommended. Tube fittings provided as standard accessories
Bushing 1.25sq 2 core cable for power supply DC24V (Cable bushing optional)



ESU Gas Detected Detection Range AGIH/TLV-TWA Part Number
Ammonia NH3 75 ppm 25 ppm GD-70D-NH3
Arsine AsH3 0.2 ppm 5 ppb GD-70D-ASH3
Boron Trichloride BCl3 15 ppm   GD-70D-BCl3
Boron Trifluoride BF3 9 ppm 0.1 ppm GD-70D-BF3
Bromine BR2 1 ppm 0.1 ppm GD-70D-BR2
Carbon Monoxide CO 75 ppm ⁕


150 ppm

300 ppm ⁕

25 ppm GD-70D-CO-



Chlorine Cl2 3 ppm


1.5 ppm ⁕

0.5 ppm GD-70D-Cl2
Chlorine Trifluoride ClF3 0.6 ppm (C) 0.1 ppm GD-70D-ClF3-A
Diborane B2H6 0.3 ppm 0.1 ppm GD-70D-B2H6
Dichlorosilane DCS 15 ppm   GD-70D-DCS
Disilane Si2H6 15 ppm (C) 2 ppm GD-70D-Si2H6
Dimethylamine (CH3)2NH 15 ppm 5 ppm GD-70D-DMA
Diethylamine (CH3CH2)2NH 15 ppm 5 ppm GD-70D-DEA
Fluorine F2 3 ppm 1 ppm GD-70D-F2
Germane GeH4 0.8 ppm (C) 2 ppm GD-70D-GeH4
Hydrogen Bromide HBr 6 ppm,
9 ppm ⁕
(C) 2 ppm GD-70D-HBR-06/-09
Hydrogen Chloride HCI 6 ppm,
15 ppm ⁕
(C) 2 ppm GD-70D-HCL-06E/15E
Hydrogen Cyanide HCN 15 ppm   GD-70D-HCN
Hydrogen Fluoride HF 9 ppm,
3 ppm ⁕
0.5 ppm GD-70D-HF-03/-09
Hydrogen Peroxide H2O2 3 ppm 1 ppm GD-70D-H2O2
Hydrogen Selenide H2Se 0.2 ppm 0.05 ppm GD-70D-H2Se
Hydrogen Sulfide H2S 1 ppm


30 ppm


1 ppm GD-70D-H2S-01/-30
Methylamine CH3NH2 15 ppm 5 ppm GD-70D-CH3NH2
Nitric Oxide NO 100 ppm 25 ppm GD-70D-NO
Nitrogen Dioxide NO2 9 ppm


15 ppm

3 ppm GD-70D-NO2-09
Nitrogen Tetraoxide N2O4 15 ppm   GD-70D-N2O4
Nitrogen Trifluoride NF3 30 ppm 10 ppm GD-70D-NF3
Oxygen O2 25% Vol. GD-70D-OXY-EC
Ozone O3 0.6 ppm 0.1 ppm GD-70D-O3
Phosphine PH3 1 ppm 0.3 ppm GD-70D-PH3-AH
Silane SiH4 15 ppm 5 ppm GD-70D-SiH4



Silicon Tetrachloride SlCl4 15 ppm   GD-70D-SiCl4
Silicon Tetrafluoride SiF4 9 ppm   GD-70D-SiF4
Sulfur Dioxide SO2 6 ppm GD-70D-SO2
Sulfur Tetrafluoride SF4 9 ppm   GD-70D-SF4
Tetraethyl Orthosilicate TEOS 15 ppm   GD-70D-TEOS
Ttrichlorosilane TCS 15 ppm   GD-70D-TCS
Trimethylamine (CH3)3N 15 ppm 5 ppm GD-70D-TMA
Tungsten Hexafluoride WF6 9 ppm   GD-70D-WF6
SGU Gas Detected Detection Range ACGIH/TLV-TWA Part Number
Carbonyl Sulfide COS 2,000 ppm GD-70D-MCOS
Dichloroethene C2H2CL2 600 ppm 200 ppm GD-70D-MC2H2Cl2
Dichlorethylene DCE 600 ppm   GD-70D-MDCE
Dichloromethane CH2CL2 2,000 ppm 50 ppm GD-70D-MDCM
Difluoromethane R-32 2,000 ppm 1,000 ppm GD-70D-MR32
Fluoro Methane R-41 2,000 ppm 1,000 ppm GD-70D-MR41
Hydrogen H2 500 ppm ⁕


1,000 ppm ⁕

2,000 ppm

2% Vol.






Isopropyl Alcohol CH3CHOHCH3 2,000 ppm 200 ppm GD-70D-MIPA-2K
Methane CH4 2,000 ppm


5,000 ppm ⁕









Methyl Alcohol CH3OH 1,000 ppm


2,000 ppm ⁕

200 ppm GD-70D-MCH3CH
Propane CH3H8 2,000 ppm


5,000 ppm ⁕

1,000 ppm GD-70D-MC3H8-2K



NCU Gas Detected Detection Range LEL % Vol. Levels  
Hydrogen H2 100% LEL GD-70D-LEL-H2
Hydrogen H2 2% Vol. GD-70D-H2-20K
Isobutane i-C4H10 100% LEL GD-70D-ISOB
Methane CH4 100% LEL GD-70D-LEL-CH4
Methane CH4 2% Vol. GD-70D-CH4-20K
SSU Gas Detected Detection Range ACGIH TLV-TWA  
Trimethyl Silane TMS 15 ppm GD-70D-TMS
Trimethoxysilane TRIMOS 15 ppm GD-70D-TRIMOS
Tetraethyl Orthosilicate TEOS 15 ppm 10 ppm GD-70D-TEOS
GD-70D (IRU) N20
Nitrous Oxide NDIR
0-500 ppm 50 ppm GD-70D-IRU-N2O

* Specifications subject to change without notice.

« Back to overview
This email address is being protected from spambots. You need JavaScript enabled to view it.