PLEASE NOTE: This product is now obsolete

Due to component obsolescence, Crowcon are unable to continue production of this product or support with spare parts for existing Gasflag units.

As an alternative solution, the Sensitron PL4+ and Gasmaster controllers are recommended.


  • Loud internal audible alarm
  • Clear system integrity indication
  • Accepts industry standard 4-20mA inputs
  • Multiple units can be daisy-chained
  • Variable alarm configurations
  • Integral alarm outputs
  • Simple installation
  • Minimum maintenance
  • One button operation


Size 210 h x 145 w x 46 d mm (8.25 x 5.75 x 1.75 inches)
Weight <500 g (1.1 lb)
Enclosure material ABS
Sensor connection Two or three wire connection to sensor via screened cable
Operating voltage 13-28 V dc
Input type 4-20 mA sink or source (selectable)
Panel indication Power Healthy         Green LED
System fault              Amber LED
Alarm 1 & Alarm 2   Red LEDs
Fault current <3 mA and >23.5 mA (overrange fault)
Operating temperature -20°C to +70°C (-4°F to +158°F)
Storage -25°C to +65°C (-13°F to +149°F)
Humidity 0-99% RH, non-condensing
Trip point hysteresis Alarm hysteresis set at approximately 0.5 mA
Fault hysteresis set at approximately 0.2 mA
Response time Time to alarm <1 second
Connections Terminals accept cables of cross sectional area 0.5 to 2.5 mm2
Relay outputs Single pole change-over for use with dc signals
The relay contacts are rated 1A at 30 V dc
Standards EMC EN50270
Ingree protection IP20


Below is a small selection of the accessories available for the Gasflag.

100-240Vac to 24V (750mA) power supply

100-240Vac to 24V (750mA) power supply


Enables Gasflag to be easily powered from a 100-240Vac mains power source. (Gasflag can also be ordered with this power supply from new, specify part number C01818 if this is required.)


Product Obsolescence Notice