The GDA 4500 is designed to be used where sensors are placed in areas that are difficult to gain access such as pits and elevated areas.

Designed, manufactured and supported locally in Australia.

The GDA 4500 is placed in an accessible location up to 50M from the filter head; this is the actual sampling point where the sample is being drawn from. The gas is drawn via 6mm ID tubing from the area that needs to be tested and is passed over the sensor element. The end of line filter prevents dust and mycological build up in the line. There is an inbuilt flow fail detector to ascertain that the vacuum pump is operational. Sensors require periodic calibration and in the case of electrochemical gas sensors they will require annual periodic replacement. The GDA 4500 can be fitted with a control unit in the same box as the sampling system that interfaces with the control to give a flow fail alarm. The remote control allows the 4500 sampling section to be adjacent to the area. The control unit to sampling unit requires a 4 core cable and can be up to 1000m from the GDA 4500 sampling unit.

  • Standalone single system gas detection system (24 VDC)
  • Many choices of gas sensor types from the GDA range of gas sensors
  • Flow fail
  • Long life dc brushless vacuum pump
  • End of line filter to prevent build up of dust in sample line
  • Local or remote control unit option
  • 3 alarm relays SPCO (volt free)
  • 1 fault relay SPCO (volt free)
  • 4-20 mA o/p
  • Mod bus RTU
  • external sounder driver
  • Mute facility with MS001

Made in Australia and Supported in Australia

Related Products

Lift Shaft Wells

Oxygen sensors are often placed in lift shaft wells to measure the atmosphere prior to entry. Problems arise due to the pressure changes in the left shaft well due to the air movements associated with the lift.resulting in false alarms . There is also an issue associated with safe work permits for access into the lift shaft area when the oxygen sensor requires calibration or replacement. The GDA 4500 system uses a vacuum pump (dc brushless) , a flow fail mechanism and a sensor  to extract the gas via a 6mm ID tubing. The Nylon tube is fitted with a filter element to provide dust filtering and prevent mycological build up in the sampling line.

Designed, Manufactured and Supported in Australia.

Specification NameSpecification Value
Detectable Gas RangesSee associated 2500 series sensor detail
Power Requirements+24 VDC
Output Types3 x SPCO for 3 alarm levels+ SPCO for fault/ flow fail
Output SpecificationsVoltage free contacts 1A 240 VAC non inductive ;4-20 mA; Modbus
Connection6mm tubing to filter head in location area
TechnologyDC brushless vacuum pump 15000hrs rated
Dimensions300 x 220 x 120 mm (L, W, D)
Enclosure MaterialABS Plastic
Enclosure RatingIP55
Cable EntryProvided by user
Max distance of sensorFrom GDA 4500 to Filter head 75 m
Gas transition timeIn 6mm ID tube linear = 8m/ Sec
Calibration RequirementAnnually with 6 monthly functional tests if senor operated at SATP
Typical Operating Life2 years before requiring sensor head replacement in standard operating environment
Warranty12 months from date of dispatch
Product Description
4500-2528 Oxygen Gas sampling system with built in control unit *
4500-2525 Carbon monoxide Gas sampling system with built in control unit
4500-2526 Ammonia Gas sampling system with built in control unit
4500-2527 Nitrogen dioxide Gas sampling system with built in control unit
4500-xxxx-R xxxx (sensor type as above) Gas sampling system with REMOTE control unit






* Important Note: Acid gases such as CO₂ and SO₂ will be absorbed by the electrolyte and tend to increase the flux of oxygen to the electrode. This gives an enhanced oxygen signal of approximately 0.3% of signal per 1% CO₂. GDA oxygen sensors are not suitable for continuous operation in concentrations of CO₂ above 25%.


M2001 : Flush Mount Mimic Panel

The M2001 is a low profile flush wall mounted mimic panel. These units are used on multi entry rooms so that users may view the gas levels and alarm status of each entry point for entering the room, used in conjunction with the GDA 4020GDA 2400 or GDA 4500 control unit.

Designed, manufactured and supported locally in Australia.

REP 2016 : Repeater Panel

The GDA Dual Channel Repeater Panel allows for simple replication of the alarm and system status of all GDA gas detection controllers by visual and auditory indicators.

Designed, manufactured and supported locally in Australia.

AVR 20 : Alarm Flasher and Sounder

This sounder/flashers operates at 24VDC. The sounder can be permanently disabled so that unit acts as a flasher only. These units are designed for internal use. These are available in Red or Amber.