Detection, Protection, Innovation

First Responder

Package includes:

  • First Responder Instrument (44526G or 44526GR)
  • G500 Carry Case (13405)
  • 4mm Hex Driver (12451)
  • 30mm Harness Assembly (12528)
  • Quick Operation Guide (42041)
  • User Handbook (42211)
  • Probe Handle Assembly c/w Filters (12481)
  • 35cm Solid End Probe (12480)
  • Cotton Filters – 2 x Boxes of 10 (10077)
  • 1.5M Tygon Tubing (12712)
  • Dust Cap Harness Assembly (42220)
  • Shipping List (42654)
  • LR20 Alkaline Battery x 4 (10278) *Dry Cell Instruments Only*
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The First Responder from GMI is a combustible gas indicator designed for emergency response technicians in the gas industry.

The First Responder detects flammable gas at PPM, LEL and % Vol levels with the addition of carbon monoxide for internal atmosphere monitoring.

An optional external range diffusion probe with high speed semiconductor sensor enables rapid response in detecting small fitting leaks.

For more info, call our sales team on +44 (0)141 302 8302.

Key Features

  • PPM , LEL and Volume flammable gas ranges for leak detection and general safety monitoring.
  • Carbon Monoxide range for internal atmosphere monitoring
  • Probe mounted Semiconductor Sensor (Range 0 – 10,000 ppm), providing instant response leak detection with audible / visual ‘Ticker’ (Geiger) alarm indication
  • Simple four button operation allowing access to all features
  • Automatic and manual datalogging


  • Leak survey
  • Gas escape detection
  • Carbon Monoxide detection

Technical Specification

Measuring Ranges

PPM  0 – 1000ppm
LEL 0 – 10%
LEL 10 – 100%
VOL 0 – 100%
EXT 0 – 1000ppm
EXT 1000 – 9999ppm

EXT = Flammable EXT Range (External Semiconductor Sensor)
Note: Hydrogen Sulphide (H2S) and Oxygen (O2) are available on request.


ex-certification-logoUL_Logo_50x50 csa-certification-logo ce-certification-logo

IEC Ex d ia IIB T3
ATEX II 2G Eex ia d IIB T3
UL913 Class 1 Div 1 Groups CD
CSA Class 1 Groups CD T3

Physical Properties

Dimensions :
180 (H) x 95 (W) x 105 (D) mm
7.1 (H) x3.7 (W) x 4.1 (D) in

1.7kg. (3.75lbs.) with alkaline batteries


0 – 95% RH non-condensing

-20oC to +50oC (-4oF to +122oF)

Sampling System

Integral pump with flow fail sensor; sample path protected by hydrophobic filter and auto pump switch off.

Power Supply

Approx. 15 hours’ runtime
Rechargeable (NiCd):
Approx. 9 hours’ runtime


Moulded polyproylene case

IP Rating



LCD with backlighting
4-digit digital display plus analogue display
3-character range indication

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