EF-301 Single Line Sample Unit

Key Features
Continuous monitoring
Flammable, oxygen or toxic gases
Easily installed and maintained
2 alarm levels & relays
4~20mA analogue output


The EF 301 system is designed to monitor gas levels in situations where the positioning of conventional gas sensors may not be practical. This may be due to equipment security, cable routing, access for detector head installation/maintenance, harsh environment or a cost effective means of monitoring designated hazardous areas, typically - tunnels, marine applications, underground/high level voids, process control, brewing, horticulture, livestock husbandry.

Additional Features

  • Line blockage and pump fail monitor
  • Delay to alarm option

Tech Specs


Combustible Gas L.E.L %Vol, ppm

Toxic Gas - ppm, %Vol

Oxygen % Vol

Power supply

230/115vAC or 24vDC ± 15%

The two voltages may be used simultaneously (standby batteries)




10 watts

Alarm Settings

Digital setting (fully adjustable between zero and full scale)

Alarm delay

T1 - 10 seconds, T2 - 30 seconds, T1 + T2 - 10 minutes


Power - Green L.E.D.

Alarms - Low/High - Red L.E.D.

Flow fail - Amber L.E.D.

Fault - Amber L.E.D.

System test alarm L.E.D’s flashing


Low alarm relay - S.P.C.O

High alarm relay - S.P.C.O

Fault alarm relay - S.P.C.O

Flow fail - S.P.C.O

Relays rated 5A/230vAC ND or NE pre set normally de energised

Analogue 4-20mA/1-5v

24vDC - 100mA max (Auxiliary equipment supply)

Audible Alarm

Low, High gas and Fault Permanent mute option

Reset Switch

Auto or Manual - pre set manual/p>

Test Switch

Used to check alarm indicators, sounder and relay action


Isolation of alarm relays during service




Ambient temperature -5 to 45˚C

Storage temperature +10 to 60˚C

Humidity range 0 - 90 RH

Cable Entry

Rear, side, top, bottom

Sample Tube

6mm OD 4mm ID

Max. length 100m

Exhaust port

8mm OD


Dimensions 315mmW 265mm H 95mm D

Weight 3.8kg

Cable entry - bottom, sides, rear

Part Codes

008-400 (4~20mA output), Particulate Condensate Trap, In-line Particulate Filter, 24v DC PSU



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