Based on the proven and highly successful Tetra product, the Crowcon Tetra 3 is designed for use in demanding industrial environments. Despite its compact size the Crowcon Tetra 3 is ultrarugged and waterproof.
Meets ATEX approvals ATEX II 2G EEx iad IIC T4 (Tamb -20°C to +55°C) BASEEFA05ATEX0187
The four gases detected by the Crowcon Tetra 3 are:
Supplied with batteries
Manufacturer: Crowcon
Part No : CROTET3-CH4-H2S-02-C0 
The Digitron P200L measures from 0-199.9mbar on the low range to 0-500mbar on the high range. Connections are push fit 4mm/0.157" I.D. 6MM/0.236" O.D. nominal, retaining nut supplied.
Certified by BASEEFA, the UK's leading ATEX approvals house, the Digitron P200L is classified as EEx ia IIC T4. This certification is equivalent to EN 50 014:1997 + Amendments 1&2 and EN50 020:2002. The units are ready for site use anywhere, immediately.
Case proven the tough construction of the Digitron P200L makes them extremely durable and, therefore functional in not only hazardous atmospheres but also rough environments.
Manufacturer: Digitron
Part No : DIGP200L 
Unlike most other ATEX-certified tools, the Fluke 87VEx can be used both inside and outside the hazardous zone (ATEX Zones 1 & 2, safety rating II 2G EEx ia IIC T4) without compromising performance or compliance, so there's no need to carry different tools for use in different areas. The Fluke 87VEx also has a built-in thermometer with TC probe, further reducing the need to purchase extra ATEX tools, which can be costly.
The key features of the Fluke 87VEx are: